Plug the measurements for the base and the height into the area formula to get A = (8)(7.5)
= 30. The correct answer is 30.
- 0 Start by multiplying the terms together. To multiply (x^2 + 2x − 3)(2x + 5), multiply each
term in the left parenthesis by each term in the right parenthesis to get 2x^3 + 5x^2 + 4x^2 + 10x
− 6x − 15. Combine like terms to get 2x^3 + 9x^2 + 4x − 15. To multiply (x + 1)(x − 1)(x + 3),
do one set of parentheses first; then multiply that product by the remaining parenthesis. You
may notice that (x + 1)(x − 1) is a common quadratic, which equals x^2 – 1. Then you need to
multiply x^2 – 1 by (x + 3). As you did before, multiply each term in the first parenthesis by
each term in the second to get x^3 + 3x^2 – x − 3. Now you can do (2x^3 + 9x^2 + 4x − 15) – (x^3
- 3x^2 – x − 3). It is easiest to distribute the negative sign into the second parenthesis: (2x^3 +
9 x^2 + 4x − 15) + (–x^3 – 3x^2 + x + 3). Now you can combine like terms to get x^3 + 6x^2 + 5x −
- This is in the form ax^3 + bx^2 + cx + d, so a = 1, b = 6, c = 5, and d = –12. This means a
- b + c + d = 1 + 6 + 5 + (–12) = 0.
- 195 Use the definition of inverse proportion: x 1 y 1 = x 2 y 2 . Plug in 1.5 for x 1 , 260 for y 1 , 2 for
x 2 , and solve for y 2 : (1.5)(260) = (2)(y 2 ); 390 = 2y 2 . Divide both sides by 2, and you find y 2
= 195.
