Answer:
Substitute the 80°F where the F is in the equation. then just put the whole equation into your calculator. I got approximately 26.7.
Direct variations can be set up as proportions
5/75 = 8/x....5 hrs to 75 dollars = 8 hrs to x dollars
now we cross multiply
(5)(x) = (75)(8)
5x = 600
x = 600/5
x = 120 <== so he makes $120 for working 8 hrs
another way...
75/5 = 15..so he makes 15 per hr
15 * 8 = 120
Lets have 4x acres of soybeans , then it is going to be 9x acres of corn
(4x/9x=4/9)
Altogether we have (4x+9x) acres
Altogether he planted 400 acres
So, we can write
4x+9x=400
13x=400
x=400/13
4x acres of soybeans
4*400/13≈123 acres of soybeans
