A would be 12. If your sister is 6 years older than your brother your brother is 4
if your brother is 1/3 your age 4 times 3 you are 12
We start by finding the intercept of the line: what does y equal when x=0? and what does x equal when y=0?
• intercept in x
y = 12 + 2x
0 = 12 + 2x
-12 = 2x
-6 = x
• intercept in y
y = 12 + 2x
y = 12 + 2(0)
y = 12 + 0
y = 12
Now we find three more points giving y a value and finding x
y = 12 + 2x
2 = 12 + 2x
2-12 = 2x
-10 = 2x
-5 = x
y = 12 + 2x
6 = 12 + 2x
6 - 12 = 2x
-6 = 2x
-3 = x
y = 12 + 2x
14 = 12 + 2x
14 - 12 = 2x
2 = 2x
1 = x
Notice how I gave y even numbers as values since we would have to divide with 2 at the end.
Sol. {(-6,0)(0,12)(-5,2)(-3,6)(1,14)}
First, we group together the terms with variables in one side by subtracting 3/2 x and 5 from both sides of the equation.
(2/3)x - (3/2)x + 5 - 5 = (3/2)x - (3/2)x - 5
(-5/6)x = -5
The value of x from the equation is 6.
