$MathMaster logo$

MathMaster

Home
general
4x21 using doubling twice strategy

Question

4x21 using doubling twice strategy

50

likes

250 views

Answer to a math question 4x21 using doubling twice strategy

$Expert avatar$

4.9

87 Answers

1. First doubling:

4 \times 21 = (2 \times 21) \times 2

2. Simplify inside the parentheses:

2 \times 21 = 42

3. Second doubling:

42 \times 2 = 84

Answer:

4 \times 21 = 84

Frequently asked questions (FAQs)

Math question: What is the derivative of the function f(x) = sin(3x) - cos(2x) at x = π/4?

+

What is the value of sinh(π/4) + cosh(2) - tanh(1) + coth(0) − sech(0) + csch(1)?

+

What is the value of x in the equation 2(x-3) + 5 = 13?

+

New questions in Mathematics

Pedro bought 9 kg of sugar at the price of R$1.80 per kilogram, six packets of coffee at the price of R$3.90 per packet and 8 kg of rice at the price of R$2.70 per kilogram. Knowing that he paid for the purchases with a R$100.00 bill, how much change did he receive?

calculate the following vector based on its base vectors a= -18i,26j

³√12 x ⁶√96

P is a polynomial defined by P(x) = 4x^3 - 11×^2 - 6x + 9. Two factors are (x - 3) and (x + 1). Rewrite the expression for P as the product of linear factors.

By differentiating the function f(x)=(x³−6x)⁷ we will obtain

4.2x10^_6 convert to standard notation

If the midpoint of point A on the x=3 line and point B on the y=-2 line is C(-2,0), what is the sum of the ordinate of point A and the abscissa of point B?

find all matrices that commute with the matrix A=[0 1]

Find the equation of the line perpendicular to −5𝑥−3𝑦+5=0 passing through the point (0,−2)

A circular window has a rubber molding around the edge. If the window has a radius of 250 mm, how long is the piece of molding that is required ? (To the nearest mm)

In a physics degree course, there is an average dropout of 17 students in the first semester. What is the probability that the number of dropouts in the first semester in a randomly selected year has between 13 and 16 students?

viii. An ac circuit with a 80 μF capacitor in series with a coil of resistance 16Ω and inductance 160mH is connected to a 100V, 100 Hz supply is shown below. Calculate 7. the inductive reactance 8. the capacitive reactance 9. the circuit impedance and V-I phase angle θ 10. the circuit current I 11. the phasor voltages VR, VL, VC and VS 12. the resonance circuit frequency Also construct a fully labeled and appropriately ‘scaled’ voltage phasor diagram.

What is the value of f(-3) for the function X squared+5x-8=

Oi👋🏻 Toque em "Criar Nova Tarefa" para enviar seu problema de matemática. Um dos nossos especialistas começará a trabalhar nisso imediatamente!

Write the inequality in the form of a<x<b. |x| < c^2

A nondegenerate ideal gas of diatomic molecules with a kilomolar mass of 2 kg/kmol and a characteristic rotational temperature of 86 K is adsorbed on the walls of a container, where the binding energy is 0.02 eV. The adsorbed molecules move freely on the walls, and their rotation is confined to the plane of the walls. Calculate the surface density of adsorbed molecules at 12 K if the gas pressure is 103 Pa! What result would you get at 68 K and the same pressure?

Emile organizes a community dance to raise funds. In addition to paying $300 to rent the room, she must rent chairs at $2 each. The quantity of chairs rented will be equal to the number of tickets sold. She sells tickets for $7 each. How much should she sell to raise money?

Find the rule that connects the first number to the second number of each pair. Apply the rule to find the missing number in the third pair. (18 is to 22) (54 is to 26) (9 is to ?)