Answer:
3x - (15 x 3) = 90
or
3x - 45 = 90
Explanation:
there are 3 boxes. We don't know how many are in them yet, so we write this as 3x. However, we know that we give away 15 to 3 different teachers. 15 x 3 = 45
Therefore the first part is 3x - 45
We also know that in the end we have 90 left.
So our final equation is:
3x - 45 = 90
Answer:
x= 2
Step-by-step explanation:
so expand the left side of the equation
9x+9= 25+x
and then group like terms( subtract 9 from both sides and also do same with x.
9x-x= 25-9
8x= 16
divide by 8 on both sides.
x=2
Answer:
37.5
Step-by-step explanation:
if it decreases by 1/2 every 8 hours;
( 3×8= 24)
the first 8 hours 1/2×300 =150 gram
the second 8 hours(16 hours) = 1/2×150=75 gram
the third 8 hours(24 hours) = 1/2×75= 37.5gram
