Question

Find the value of y for a given value of x, if x varies directly with x. If y=39 when x=-117 what is y when x=-132

my answer
y=k*x
39=k*-117
39/-117=k
k=-0.3
y=k*x
y=-0.3*-1.32
y=-3.96 can someone please check my work

Answer 1

except for the decimal point which you inserted (1.32 instead of 132 as shown at the top) it looks ok.

Answer 2

oh ok thanks for catching my mistake

Answer 3

so should be 39.6

Answer 4

or, -39.6

gotta watch the details.


In fact, your lines

y=-0.3*-1.32
y=-3.96

were also off; should have been -0.396

so, even if you had been correct using 1.32, your answer would <i>still</i> have been wrong! :-(

Answer 5

this is what i got

y=39
x=-117
y when x=-132

39/-117=k
k=-0.3

y=-0.3*-132
y=39.6

Answer 6

Steve can you recheck my answer

Answer 7

oops my bad. You are correct. I missed the "-" on -132.