7a)
x - 10 + x - 11 + 3x + 6 = 180
5x -15 = 180
5x = 195
x = 39
7b)
y = 3x + 6
y = 3(39) +6
y = 117 + 6
y = 123
We know that
<span>1 1/8 gallons----------> (1*8+1)/8-------> 9/8 gallons
</span><span>13 1/2 miles----------> (13*2+1)/2-------> 27/2 miles
if 9/8 gallons-------------------> 27/2 miles
1 gallons----------------------> X
X=(27/2)/(9/8)---------> 216/18--------> 12 miles
the answer is 12 miles</span>
Rewrite the equations;
m+4n=8
m-n=-2
Eliminating m gives;
5n=10
n=2
Replacing for n in the first equation;
m+4(2)=8
m=8
Answer;
(0, 2)
