Answer: 
<u>Step-by-step explanation:</u>
EQ1: x + y = 12 --> x = 12 - y
EQ2: xy = 15
Substitute x = 12-y into EQ2 to solve for y:
(12 - y)y = 15
12y - y² = 15
0 = y² - 12y + 15
↓ ↓ ↓
a=1 b= -12 c=15
Now, let's solve for x:
Lastly, find x² + y² :
Y= mx+b
Since this line is horizontal it's slope = 0 ==> the y=b
It passes by the point (3,-3) that means b=-3 & the equation is y=-3
We need to know how much tax she must pay based on her taxable income ,
Since un the table it states that taxable incomes that range between $0-$132000have a tax rate of 18% of each $1 .
We already know her taxable income that is = 129000, which ranges between 0 and 132000.
Hence we know how much tax she must pay .
First , we need to calculate how much 18% of $1 is
= 18/100 x 1 = $0.18
Per annum/year = $0.18 x $129,000 = $23,220
Per month = $23,220 / 12 = $1,935
Hope you found this helpful , good luck !
