Answer:
√7x−49√x
Explanation:
First of all, expand by multiplying √7x⋅√x and √7x⋅7√7respectively:
√7x(√x−7√7)=√7x⋅√x−√7x⋅7√7
... you can express √7x as √7⋅√x...
=√7⋅√x⋅√x−√7⋅√x⋅7⋅√7
=√7⋅(√x)2−(√7)2⋅√x⋅7
... the operations squaring and taking the square root "eliminate each other"...
=√7⋅x−7⋅√x⋅7
=√7x−49√x
Hope that this helped!
Answer:
500 and 900
Step-by-step explanation:
3(x - 300) + 2(x + 100) = 3300 ← distribute parenthesis
3x - 900 + 2x + 200 = 3300
5x - 700 = 3300 ( add 700 to both sides )
5x = 4000 ( divide both sides by 5 )
x = 800
Then
cost of book = x - 300 = 800 - 300 = 500
cost of pen = x + 100 = 800 + 100 = 900
