"31-inch piece of steel is cut into three pieces"
Call the pieces a,b,c
a + b + c = 31
"second piece is twice as long as the first piece"
b = 2a
"third piece is one inch more than seven times the length of the first piece"
c = 1 + 7a
Ok, we have our equations, let's substitute the second and third into the first.
a + 2a + 1 + 7a = 31
10a + 1 = 31
10a = 30
a = 30/10 = 3
b = 2a = 6
c = 1 + 7a = 22
Check: 3 + 6 + 22 = 31, good
Answer: 3 inches, 6 inches, 22 inches
Answer: plants are same height in 30 days; Plant A is tallest in 6 weeks
Step-by-step explanation:
x = number of days
4 + (2/3)x = 9 + (1/2)x
(2/3)x - (1/2)x = 9 - 4
(1/6)x = 5
x = 30, number of days for Plant A and Plant B to be same height.
6 wks = 42 days
Plant A in 42 days: 4 + (2/3)(42) = 32 inches
Plant B in 42 days: 9 + (1/2)(42) = 30 inches
ok so the answer is A well i think it is at least this one is hard and im sorry if i got it wrong bc i did the math in my head.lol