(-3y^2 − 8) − (-5y^2<span> + 1)
= </span>-3y^2 − 8 + 5y^2<span> - 1
= 2</span>y^2 <span>- 9
answer is
</span>2y^2 - 9<span>
</span>
Answer:

Step-by-step explanation:

The first set of parentheses is unnecessary, so it can just be removed.

To remove the second set of parentheses, you must distribute the negative sign that is to its left. It changes every sign inside the parentheses.

Now you combine like terms.


Answer:
Step-by-step explanation:
Find the sum of the first 42 terms of the following series, to the nearest integer.
2,7,12
Solution
The sum is given by
SUM_n=n/2*(a_1+a_n)
a_n=a_1+(n-1)d
a_1=2, n=42, d=5
The 42nd term is therefore given by
a_42=2+(42-1)5=207
SUM_42=42/2*(2+207)=21*209=4389
The sum of the first 42 terms of the series, therefore, is 4389
Answer:
w-15
Step-by-step explanation:
-3 * ( w + 5) + 4w
Distribute the -3 to each term in the parentheses
-3w -15 + 4w
Combine like terms
-3w+4w -15
w-15
Answer:
12.5%
Step-by-step explanation:
% increase = (new value - initial value)/initial value x 100
= (90-80)/80 x 100
=10/80 x 100
= 12.5%