Rounding or compatible numbers to estimate the sum 18 53

Find the sum of the geometric series 1 + 0.8 + 0.8^2 + 0.8^3 + ... + 0.8^{19}

Substitution method x = - 2y 2x+5y=-1

What's 4 to the power or 5

Luke's dad need 165 for a new suitcase. If he saves an equal amount for 3 weeks, how much does save each week?

What is a 25% decrease from 60

Which relation is a function? A. (6, 5), (1, 1), (6, 4) B. (0, 1), (2, 3), (2, 5) C. (8, - 2), (-2, 5), (6, 0) D. (-2, 3), (-5, 9), (-5, 3)

Given tanx = 7/24. What is csc X

the population of the US was 282 million in the year 2000. and 309 million in the year 2010. assuming that the US population follows the model of uninhibited population growth, what will the population be in the year 2050?

X+5/5=x+9/7 x equals?

In the similar triangles used in indirect measurement with the shadows of a flagpole and a person, which sides of the triangles represent the rays of the sun?