Ok, so the quadratic coefient is 1, so great
take 1/2 of the linear coefient and square it
10/2=5, (5)^2=25
add that to both sides
x^2+10x+25=7+25
factor perfect square trionomial
(x+5)^2=32
squaer root both sides
x+5=+/-4√2
minus 5
x=-5+/-4√2
x=-5+4√2 and -5-4√2
Answer: ![(-\infty, -4]](https://tex.z-dn.net/?f=%28-%5Cinfty%2C%20-4%5D)
Curved parenthesis at negative infinity
Square bracket at -4
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Work Shown:

The last inequality shown above is the same as saying 
Converting this to interval notation leads to the final answer of ![(-\infty , -4]](https://tex.z-dn.net/?f=%28-%5Cinfty%20%2C%20-4%5D)
Note the use of a square bracket at -4 to include this endpoint. We can never include either infinity, so we always use a parenthesis for either infinity.
Answer:
F = 48
Step-by-step explanation:
F= 8/5 (c) + 40
Let c=5
F = 8/5 * 5 +40
= 8 + 40
= 48
Let's take the percentage as x
(x / 100) * 5 = 0.35
x / 100 = 0.07
x = 7
therefore the percentage is 7%