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
So y=mx+b
m=slope
y=-3x+b
subsitutue 1 for x and 4 for y
4=-3(1)+b
4=-3+b
add 3 to both sides
7=b
the equaiton is y=-3x+7
Answer:
see explanation
Step-by-step explanation:
Given
2x² + 7x = 15 ( subtract 15 from both sides )
2x² + 7x - 15 = 0 ← in standard form
To factorise the left side
Consider the factors of the product of the coefficient of the x² term and the constant term which sum to give the coefficient of the x- term
product = 2 × - 15 = - 30 and sum = + 7
The factors are + 10 and - 3
Use these factors to split the x- term
2x² + 10x - 3x - 15 ( factor the first/second and third/fourth terms )
2x(x + 5) - 3(x + 5) ← factor out (x + 5) from each term
(x + 5)(2x - 3) ← in factored form
