Find the value of the expression 21 - 2a if a = 3

Choose the correct sum of the polynomials (2x3 - 5x - 1) + (4x + 8x + 3). O 2x3 - 3x - 4 O 6X® + 3x + 2 2x3 + 3x + 2 O 6x3 - 3x - 2

The sum of a number times 6 and 19 is at least - 29

Given that R=2x+9y Find x when y=3 and R=13.

How can I write an equivalent expression for 4+3 (5 + x)

What is c=-6 and x=4 - 4*+c

What is the solution to the system of equations? Use the substitution method. {y=-2x+5 {3x-4y=2 Enter your answer in the boxes.

Absolute value of - 1 + 3i

Round 64,569 to the thousands

Keenan received two cube shape packages in the mail. The first package measured half the side lengths of the first. What was the volume of the second package Keenan received?

Dan was 8 years old when his sister was born. Now the sum of their ages is 56. Write an equation to represent this problem. Let the sister's age be s.