24- sqrt(720/4) divide 720 by 4
24 - sqrt (180) now break down 180 to 9*4*5
24- sqrt(9) *sqrt(4) *sqrt (5) so 9becomes 3, 4 becomes 2
24- 3*2*sqrt(5) multiply 3 and 2
24-6sqrt(5)
The arrows should start at zero because then the expression wouldn't be true. She should have made 5 groups if she had started at zero.
The lines have equal gradients;
m

Equation of line 2;
y=mx+c
y=

x+c
-15=

+c
c=-11
y=4/5x-11
Y=2.5r+50
Y is the total points
2.5 is the rate
r is the amount of questions he got right 50 is the score he already earned