How to solve two-step equations with decimals in pre-algebra

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Math › How to solve two-step equations with decimals in pre-algebra

Questions 1 - 4

1

Josie buys worth of groceries. The sales tax is . If she pays with , how much change should she get?

Explanation

The sales tax is $12.38\cdot 0.03875=0.479$

The total grocery bill is .

The change is .

2

Solve the equation for . (Round to two decimal places).

$\small 1.22n+4=3.5$

$\small n=-0.41$

$\small n=0.41$

$\small n=6.15$

$\small n=-6.15$

Explanation

$\small 1.22n+4=3.5$

Subtract from both sides of the equation, and simplify.

$\small 1.22n+4-4=3.5-4$

$\small \small 1.22n=-0.50$

Divide both sides by . Be careful of the negative sign.

$\small \frac{1.22n}{1.22}=-\frac{0.50}{1.22}$

$\small n=-0.41$

3

Explanation

This is a two-step equation. First you must add the decimals up to have a singular variable element

$\left ( 2.4+1.6\right )X=16$

Then divide both sides by 4:

$\frac{4X}{4}=\frac{16}{4}$

4

Solve for

Explanation

The goal is to get alone on one side. Therefore you subtract from both sides to get . Then divide both sides by to get alone.

.

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