For this case we must resolve the following inequality:

Adding 7 to both sides of the inequality:

Different signs are subtracted and the major sign is placed.

Thus, the solution is given by all the values of "x" less than -5.
The solution set is: (-∞, - 5)
Answer:

See attached image
Answer:
0.74 to 6.06
Step-by-step explanation:
The groups are independnet,
SE(xh bar-xa bar)=sqrt [sh^2/nh+sa^2/na]=sqrt [10.1^2/80+10.3^2/80]=1.61
At df=157, the t critical is 1.65
90%c.i=(xh bar-xa bar)+-tcritical SE(xh bar-xa bar)
=(25.2-21.8)+-1.65*1.61
=0.74 to 6.06
Answer:
f(x) = - 9x² + 9
g(x) = 8x² + 9x
To find (f+g)(x) add g(x) to f(x)
That's
(f+g)(x) = -9x² + 9 + 8x² + 9x
Group like terms
(f+g)(x) = - 9x² + 8x² + 9x + 9
<h3>(f+g)(x) = - x² + 9x + 9</h3>
To find (f + g)(- 1) substitute - 1 into (f+g)(x)
That's
(f + g)(- 1) = -(-1)² + 9(-1) + 9
= - 1 - 9 + 9
<h3>= - 1</h3>
Hope this helps you