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Solve for x
-10x= 2 (9 - 2x)
A: 3
B: 9/7
C: -3
D: -9/7

User Krsi
by
4.9k points

1 Answer

1 vote

Answer:

c.) x = -3

Explanation:

Solve for x:

-10 x = 2 (9 - 2 x)

Hint: | Write the linear polynomial on the left hand side in standard form.

Expand out terms of the right hand side:

-10 x = 18 - 4 x

Hint: | Move terms with x to the left hand side.

Add 4 x to both sides:

4 x - 10 x = (4 x - 4 x) + 18

Hint: | Look for the difference of two identical terms.

4 x - 4 x = 0:

4 x - 10 x = 18

Hint: | Combine like terms in 4 x - 10 x.

4 x - 10 x = -6 x:

-6 x = 18

Hint: | Divide both sides by a constant to simplify the equation.

Divide both sides of -6 x = 18 by -6:

(-6 x)/(-6) = 18/(-6)

Hint: | Any nonzero number divided by itself is one.

(-6)/(-6) = 1:

x = 18/(-6)

Hint: | Reduce 18/(-6) to lowest terms. Start by finding the GCD of 18 and -6.

The gcd of 18 and -6 is 6, so 18/(-6) = (6×3)/(6 (-1)) = 6/6×3/(-1) = 3/(-1):

x = 3/(-1)

Hint: | Simplify the sign of 3/(-1).

Multiply numerator and denominator of 3/(-1) by -1:

Answer: x = -3

User Leoluk
by
5.2k points
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