Using linear combination method to solve the system of equations 3x - 8y = 7 and x + 2y = -7 is (x, y) = (-3, -2)
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Given that, a system of equations are:
3x – 8y = 7 ⇒ (1) and x + 2y = - 7 ⇒ (2)
We have to solve the system of equations using linear combination method and find their solution.
Linear combination is the process of adding two algebraic equations so that one of the variables is eliminated. Addition or subtraction can be used to perform a linear combination.
Now, let us multiply equation (2) with 4 so that y coefficients will be equal numerically.
4x + 8y = -28 ⇒ (3)
Now, add (1) and (3)
3x – 8y = 7
4x + 8y = - 28
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7x + 0 = - 21
7x = -21
x = - 3
Now, substitute "x" value in (2)
(2) ⇒ -3 + 2y = - 7
2y = 3 – 7
2y = - 4
y = -2
Hence, the solution for the given two system of equations is (-3, -2)
From the looks of it, I believe it is either 120, 125, or 126. If you have options, let me know so I can take a closer look.
Answer:
30 degrees
Step-by-step explanation:
Answer:
2t + 4f = 100
t+f =42
Step-by-step explanation:
t= two point questions
f =four point questions
2t + 4f = 100
t+f =42
there are 34 two point questions and 8 four point questions
to solve multiply the second equation by -2
-2t -2f = -84
add this to 2t +4f = 100
2t + 4f = 100
-2t -2f = -84
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2f = 16
divide by 2
f = 8
there are 8 four point questions
t+f=42
t+8 = 42
subtract 8
t = 34
there are 34 2 point questions
