Exercise 38 Page 9

Use the Multiplication Property of Equality.

x=-2.8

Practice makes perfect

To solve the given equation for x, we need to isolate it by multiplying both sides of the equation by -2. We want to multiply by -2 because division and multiplication are inverse operations — they cancel each other out. This is allowed by the Multiplication Property of Equality.

x÷(-2)=1.4

WriteAsFrac

Write as a fraction

x/- 2=1.4

MultEqn

LHS * (-2)=RHS* (-2)

x/- 2(- 2)=1.4(- 2)

FracMultDenomToNumber

a/- 2* - 2 = a

x=1.4(- 2)

MultPosNeg

a(- b)=- a * b

x=-2.8

We will check our solution by substituting this result back into the original equation and simplifying. If doing so results in an identity, our solution is correct.

x÷(-2)=1.4

Substitute

x= -2.8

{\color{#0000FF}{\text{-}2.8}}\div(\text{-}2)\stackrel{?}=1.4

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Calculate quotient

WriteAsFrac

Write as a fraction

\dfrac{\text{-} 2.8}{\text{-} 2}\stackrel{?}=1.4

DivNegNeg

- a/- b=a/b

\dfrac{2.8}{2}\stackrel{?}=1.4