5 + (-21) = what's the answer

The difference of two rational numbers is always negative true of false

So i have to factor 49x^16 - 167^64 and the answer is : (7x^8-4y^32) x (7x^8+4y^32) is it a X or is it the multiply sign? and do i add that with the answer or no?

A tent in the shape of a triangular prism has a square base with a side of 8 feet and a height of 6 feet. What is the volume?

Jill had $125 to spend at the mall. She spent 27% of that money on a pair of shoes. Jill spent $___ on the shoes. (Make sure to enter the answer as a decimal number only. Do not enter special characters such as the dollar symbol.)

What is the difference? x-8/3x - 3x/x2

Make d the subject of the formula a=cd

What is 5x-9=7x+6-2x

A regular pentagonal prism has a height of 12 in. and base edge length of 8 in. Identify its lateral area and surface area. L = 576 in2; S = 700.2 in2 L = 480 in2; S = 590.1 in2 L = 480 in2; S = 700.2 in2 L = 576 in2; S = 590.1 in2

An uncooked gingerbread cookie is y centimeters long. After it is baked, the length of the cookie increases by 25%. Which expression best represents the new length of the cookie? A. 0.25y B. 0.75y C. 1.25y D. 12.5y

Lin has 13 coins in her pocket that equal 40 cents. All the coins are dimes, d, and pennies, p. Which combination of coins does Lin have? Use the table to answer the question.