Complete question is;
Henrique began to solve a system of linear equations using the linear combination method. his work is shown below
1. 3 (4x-7y=28) -> 12x-21y=84
-2 (6x-5y=31) -> -12x 10y =62
2. 12x - 21y = 84
-12x + 10y = -62
-----------------------
-11y = 22
3. y= -2
complete the steps used to solve a system of linear equations by substituting the value of y into one of the original equation s to find the value of x. what is the solution to the system
Answer:
x = 3.5
Explanation:
We are given;
1. 3(4x - 7y = 28) -> 12x - 21y = 84
-2(6x - 5y = 31) -> -12x + 10y = 62
2. 12x - 21y = 84
-12x + 10y = -62
-----------------------
-11y = 22
3. y= -2
Since y = - 2, let's put -2 for y into the equation; 12x - 21y = 84
This gives;
12x - 21(-2) = 84
This gives;
12x + 42 = 84
12x = 84 - 42
12x = 42
x = 42/12
x = 3.5