The price of a brick today is 49 cents. This is 3 cents less than 4 times the price 20 years ago. What was the price 20 years ago?

Question

The price of a brick today is 49 cents. This is 3 cents less than 4 times the price 20 years ago. What was the price 20 years ago?

1 Answer

Impact of this question

3847 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2017-12-11T11:44:46

$13 cents$ $13" cents"$

Explanation:

$let the cost of a brick 20 years ago = c$ $"let the cost of a brick 20 years ago "=c$

$\Rightarrow 4 c - 3 = 49 \leftarrow solve for c$ $rArr4c-3=49larrcolor(blue)"solve for c"$

$add 3 to both sides$ $"add 3 to both sides"$

$4c cancel(-3)cancel(+3)=49+3$

$rArr4c=52$

$"divide both sides by 4"$

$(cancel(4) c)/cancel(4)=52/4$

$rArrc=13$

$"the cost of a brick 20 years ago was "13" cents"$

$color(blue)"As a check"$

$(4xx13)-3=52-3=49$

Science

Math

Humanities

... and beyond

The price of a brick today is 49 cents. This is 3 cents less than 4 times the price 20 years ago. What was the price 20 years ago?

1 Answer

Explanation:

Related questions

Impact of this question