<span>2x-3y=18
when x = 3
2(3) - 3y = 18
6 - 3y = 18
-3y = 12
y = -4
so(3, -4) is the solution
answer
</span><span>(3,-4)</span>
Question 14, Part (i)
Focus on quadrilateral ABCD. The interior angles add to 360 (this is true for any quadrilateral), so,
A+B+C+D = 360
A+90+C+90 = 360
A+C+180 = 360
A+C = 360-180
A+C = 180
Since angles A and C add to 180, this shows they are supplementary. This is the same as saying angles 2 and 3 are supplementary.
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Question 14, Part (ii)
Let
x = measure of angle 1
y = measure of angle 2
z = measure of angle 3
Back in part (i) above, we showed that y + z = 180
Note that angles 1 and 2 are adjacent to form a straight line, so we can say
x+y = 180
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We have the two equations x+y = 180 and y+z = 180 to form this system of equations

Which is really the same as this system

The 0s help align the y terms up. Subtracting straight down leads to the equation x-z = 0 and we can solve to get x = z. Therefore showing that angle 1 and angle 3 are congruent. We could also use the substitution rule to end up with x = z as well.
X > -8
The line would be on -8 going to the left, the circle would not be shaded
Using a system of equations, it is found that Peter had $48 at first.
<h3>What is a system of equations?</h3>
A system of equations is when two or more variables are related, and equations are built to find the values of each variable.
In this problem, the variables are:
- Variable x: Peter's money.
- Variable y: Henry's money.
The ratio of peters money to henrys money is 4 : 3, hence:

After Peter spent $12, they had the same amount, hence:
y = x - 12.
Then, replacing in the ratio:


4(x - 12) = 3x
x = 48.
More can be learned about a system of equations at brainly.com/question/24342899
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