1000 j etyuu was the night of my school week I am so
So we solve for each
70% of 100=70
students who didn't buy lunch=100-70=30
some of the 70 left so that the students who bought lunch, are 60% of those who are left
we know that the students who didn't buy lunch didn't change number so therefor
100% of students left-60%=40%= students that didn't buy lunch=30 so
40%=30
20%=15
100%=75
there were 75 students lfet in the cafeteria
Let
x--------------> a number
we know that
<span>three sets of a sum of a number and four----------> 3(x+4)
t</span><span>he sum of 7 times the same number and 13--------> 7x+13
therefore
</span>(Three sets of a sum of a number and four) are added (to the sum of 7 times the same number and 13) ----------> [3(x+4)] + [7x+3]
[3(x+4)] + [7x+3]------> [3x+12] + [7x+3]=10x+15
the answer is 10x+15
