If 4a=5b^3=40 what is the value of ab^3?

Test Preparation SAT Preparation
1

<p>A) 10
b) 20
c) 40
d) 80
e) 160</p>

2

<p>NEVERMIND :slight_smile: I figured it out it’s D</p>

3

<p>Just confirming that you are right . . . quite a few of the questions are like this–superficially difficult, but actually readily solvable.</p>

4

<p>Wow. How did you solve it, nativegirl?</p>

5

<p>4a=5b^3=40
Since you already know how to solve it, I’ll demonstrate the steps to the people who don’t know.
We know:
4a=40
5b^3=40
We can simplify:
a=10
Times “a” to both sides
5b^3•a=40•a
Simplify right side:
5ab^3=40•10=400
Divide both sides by 5:
ab^3=80</p>

<p>Here is the answer!</p>

6

<p>I realize there is an easier method…
4a=40
5b^3=40
=>a=10
=>b^3=8</p>

<p>ab^3=10•8=80</p>

<p>Curse my over thinking brain.</p>

7

<p>Lol sorry guys just realized I had responses but kudos :)</p>