Solve the following system using any method.
8a - 4b = 20 5a - 8b = 62

question 5 options:

a = 5, b = -4

a = 8, b = 4

a = -5, b = -8

a = -2, b = -9

a=-2 and b=-9

Step-by-step explanation:

To solve the system, substitute one equation into another.

8a -4b = 20 becomes -4b = 20 - 8a. Dividing by -4 on both sides, b = 2a-5.

Now substitute the equation b=2a-5 into 5a - 8b = 62.

5a - 8(2a-5) = 62

5a - 16a + 40 = 62

-11a + 40 = 62

-11a = 22

a=-2

To find b, substitute a=-2 into b=2a-5.

b = 2(-2) - 5

b = -4 - 5

b = -9

overpriced

step-by-step explanation:

proportions are fractions that equal to each other. so if two fractions are the same, they are proportional.

let's check the answers to see if they are proportional.

question a is not proportional because you can't turn 1.5/3 to 3/9. if you try to multiply 1.5/3 by 2 or 3, you wont get 3/9. it's impossible to make the fractions the same.

question b is not proportional because you can't turn 22/33 to 4/6. 33 can't go into 6.

question c is proportional because when you multiply 2 and 3 by 71, you would get 142/213, and those fractions equal to each other

question d is proportional because when you divide 14 and 7 by 2, you would end up with 7/3.5, and those fractions equal to each other.