Answer:
42x-39
Step-by-step explanation:
This is a system of equations. You can solve it by substitution or elimination. I'm going to use substitution x - 2y = -4.5; add 2y to each side x - 2y + 2y = -4.5 + 2y; simplify x = 2y - 4.5 2(2y - 4.5) + 3y = 12 4y - 9 + 3y = 12 7y - 9 = 12 7y - 9 + 9 = 12 + 9 7y = 21 y = 3 <--------first answer x - 2y = -4.5 x - 2(3) = -4.5 x - 6 = -4.5 x -6 + 6 = -4.5 + 6 x = 1.5 <--------second answer Check: 2(1.5) + 3(3) = 12? 3 + 9 = 12? 12 = 12; It checks 1.5 - 2(3) = -4.5? 1.5 - 6 = -4.5? -4.5 = -4.5; It checks x = 1.5 and y = 3 <-----------Final Answer
11) the product of 77 and h
12) the difference between x and 5 times of f
13) the quotient of the dividend x and divisor 2
14) the difference between m and 22
15) the difference between 7 times of x and 3
Answer:
The formula for the area of a square with sides of length x is A = x2 so
x2 = 400 is the equation
This equation has 2 solutions, namely x = ±√400 = +20 or -20
The negative solution does not make sense because a length cannot be less than 0.
The total length needed to go around the painting is the perimeter of the square, which is
P = 4*x = 4*20 = 80 inches
