19. N = 7LH....solve for H
N / 7L = H
estimate : L = 28..gonna round it to 30, N = 1568..gonna round it to 1570
1570 / 7(30) = 1570/210 = 7.48..so its about 7 1/2 ft tall.
20. D = M/V
D = 19.3
M = 96.5
19.3 = 96.5/V....multiply both sides by V, eliminating V on right side
19.3V = 96.5 ...divide both sides by 19.3
V = 96.5 / 19.3
V = 5 g/cm^3
21. P = 2L + 2W....solve for w
subtract 2L from both sides
P - 2L = 2W
divide both sides by 2
(P - 2L)/2 = W or P/2 - 1 = W or 1/2P - 1 = W
22. -3(m - 2n) = 5m
-3m + 6n = 5m
6n = 5m + 3m
6n = 8m
6/8n = m
3/4n = m <==
EC1.
y = 3x + 1......when x = 1 and y = 4...this is correct......but the solution is written as (x,y)...so the solution is (1,4) and NOT (4,1)
EC2.
55.20 = 3(5.30g) + 2.50(3)
55.20 = 15.9g + 7.5
55.20 - 7.5 = 15.9g
47.70 = 15.9g
47.70/15.9 = g
3 = g.....so they played 3 games