Step by step
The question
Question: simplify (x³y)².
(x3y)2
1 Write the power out
The power 2 outside the bracket means: the whole bracket, 2 times.
(x3y)2 = (x3y)(x3y)
So we write the bracket out, times itself.
= ((x3y))((x3y))
2 Count the letters
A power tells how many times the letter is multiplied.
x³ is 3 x's.
x³ is 3 x's.
Together that is 6 x's.
x3 x3 = (xxx)(xxx) = x6
y y = (y)(y) = y2
So the rule is: same letter, times, add the powers.
3 plus 3 is 6.
For y: 1 plus 1 is 2.
3 + 3 = 6
y: 1 + 1 = 2
xa xb = xa + b
3, added 2 times, is 3 times 2.
So for a power of a power, the rule is: multiply the powers.
3 × 2 = 6
(xa)b = xa × b
So we get x⁶y².
= x6y2
Let's look back.
First: write the power out.
Last: count the letters.
Answer
= x6y2