Answer:
10. 2x+y
11. x^2-15x+3
Step-by-step explanation:
10. when u add 7x+3y and 4x+4y you will get 11x+7y. 13x+8y minus 11x+7y will be 2x+y
11. when u add 3x^2+7x+1 and x^2-x+1 u will get 4x^2+6x+2. 5x^2-9x+5 minus 4x^2+6x+2 will be x^2-15x+3
Answer:
Pretty Simple!
Now that you know about ratios and all that, this is pretty tame compared to the last problem.
Now, the problem is talking 2D(2 Dimensions)
The ratio is not going to work because it has only one parameter.
Thus, we need to square it!

Thus, we have your correct ratio.
Now, we only need to do the same thing for the triangle problem. Meaning that, we need to compare the ratios, with x as the thing we are looking for.

See? X is practically handed to us.
Hope this helps!
Answer:
x = 8, y = 
Step-by-step explanation:

Both 8 and x sides are congruent so they're equal.
Add 64 + 64.
Square root 128

Final answers: x = 8, y = 
31a) Think of $30.90 as 100% of her bill, we first want to find 6%
To work out how much this is, we need to divide the percentage by 100 to get a multiplier (decimal)
6/100 = 0.06
Multiply 0.06 and $30.90 to get the tax
$30.90 x 0.06 = 1.854
As we can't have part of a cent, we round to the nearest 100th
If the number to the right of this value is below 5 we round down, 5 or more we round up
4 is below 5 so we round down
$1.85
31b) For the total bill, we need to add together the original and the tax
$30.90 + $1.85 = $32.75
32a) Simple Interest = PRT
This means
P x R x T
We need to multiply together the Principal, Rate and Time span
We need to turn the percentage into a decimal, so we divide by 100 like before
3.2 / 100 = 0.032
$750 x 0.032 x 6 = $144
32b) To find the account balance, we need to add the interest to the original amount
$750 + $144 = $894
The slope is 4.
To find the perpendicular slope, you use the negative reciprocal of the slope you already have. Since the original slope is -1/4, you flip -1/4 to get -4. You then find the negative of -4 to get 4