<span>y = 2x + 20. The answer is A. Explanation: Vlad spends a known amount of time on his history homework (20). On top of it, he also spends an unknown amount of time on solving a number of math problems (x). Each problem takes two minutes to solve, so the amount of time that he spends solving math problems is 2*x or 2x. In total (y), Vlad spends 20 + 2x amount of time on his homework. So y = 2x + 20, where y is clearly greater or equal to 20 and x is greater or equal to 0.</span>
Answer: 87%
Solution:
87 correct questions over 100 = 87/100 = .87 = (change to percent by moving the decimal 2 places to the right) 87%
X² + mx + m A perfect square trinomial is where:x² - is the square of the first term binomialmx - is twice the product of the binomials first and last termm - is the square of the last term binomial
x² + mx + m = (x + 1)²
(x + 1)² ⇒ (x+1)(x+1) = x(x+1) +1(x+1) ⇒ x² + x + x +1 = x² + 2x + 1