Answer:
Step-by-step explanation:
9x⁴ – 2x² – 7 = 0
Let's say that u = x²:
9u² – 2u – 7 = 0
Factor:
(u – 1) (9u + 7) = 0
u = 1, -7/9
Since u = x²:
x² = 1, -7/9
x = ±1, ±i √(7/9)
A) One solution: 5x +2y = 0 . . . . (any line with a different slope)
b) Two solutions: not possible
c) No solutions: 5x -2y = 0 . . . . (any different line with the same slope)
d) Infinitely many solutions: 10x -4y = 6 . . . . (any other equation for the same line)
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
Answer:
feet
Step-by-step explanation:
