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Multiple Choice
Use substitution to solve the following system of linear equations. 4x+2y=7 x+5y=4
A
(21,23)
B
(23,21)
C
(−32,31)
D
(−31,32)
3 Comments
Verified step by step guidance
1
Start by identifying the two equations in the system: 4x + 2y = 7 and x + 5y = 4.
Choose one of the equations to solve for one variable in terms of the other. Let's solve the second equation, x + 5y = 4, for x. Subtract 5y from both sides to get x = 4 - 5y.
Substitute the expression for x from the second equation into the first equation. Replace x in 4x + 2y = 7 with 4 - 5y, resulting in 4(4 - 5y) + 2y = 7.
Simplify the equation from the previous step. Distribute the 4 to get 16 - 20y + 2y = 7. Combine like terms to simplify further: 16 - 18y = 7.
Solve for y by isolating it on one side of the equation. Subtract 16 from both sides to get -18y = 7 - 16, which simplifies to -18y = -9. Divide both sides by -18 to find the value of y.