Question

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Find the solution to the system of equations.
21x+7y=42
−5x+5y=10
​

Answer 1

x = 1 and y = 3

Explanation:

Use two equations with two unknown rule or simply write both in Geogebra in the computer system CAS (computer algebra system) and solve for x-values. You then get x = 1 and y = 3

GOOD luck!

Astrophysicist Dr. D

Answer 2

-5x+5y=10
add 5x
5y=5x+10
divide by 5
y=x+2

substitute into the other equation
21x+7(x+2)=42
distribute
21x+7x+14=42
add like terms
28x=28
divide by 28
x=1

substitute into any equation
-5(1)+5y=10
perform multiplication
-5+5y=10
add like terms
5y=15
divide by 5
y=3

(1,3)