Question

P

Jimmy tried to solve the system of equations below, but he made an error
S 2.0
y=18
y= 40 +2
His work is shown. Find the error he made. Explain the error and show how to solve the sysm correctly.
1. 2.0 - 4.3 + 2 = 18
2.-2x = 16
3. = -8
4. y=4(-8) + 2
5. Y = -32 +2
6. y=-30
7. Check: 2 (-8) - (-30) = 18
8.
- 16 + 30 = 18
9 14 + 18
His mistake was on Line
because he should have
The correct solution is

Answer 1

"His mistake was on line 1. He didn't distribute the negative sign (indicating a -1) to everything in the equation for y."

The correct solution is: x = -10, y = -38

Explanation:

2x - y = 18

y = 4x + 2

Substitute the given value for y into the first equation:

2x - (4x + 2) = 18

2x - 4x - 2 = 18 ** here, he didn't distribute the (-) to everything in the parentheses that represents y

-2x -2 = 18

add 2 to both sides

-2x = 20

divide by -2

x = -10

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solve for y

y = 4x + 2

y = 4(-10) + 2

y = -40 + 2

y = -38

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Check the math:

2x - y = 18

2(-10) - (-38) = - 20 + 38 = 18