He used the property of addition. Hope this helps. Please mark me as brainliest if I am right.
Answer: It’s 1
Explanation: it’s 1
One solution
The two (or more) equations would only intersect once
No solution
Lines never intersect
The lines are parallel
Infinite solutions
The lines are the exact same
That’s all the characteristics I know
1.50s + 0.75f = 116.25
2f = s
1.50(2f) + 0.75f = 116.25
3f + 0.75f = 116.25
3.75f = 116.25
f = 116.25/3.75
f = 31...31 friday papers
2f = s
2(31) = s
62 = s <=== 62 sunday papers
C reflex because it goes over 180 degrees!