Answer:
x=20
Step-by-step explanation:
H = -16t² + 64t + 80 (:16)
H = -t² + 4t + 5
/\ = b²-4ac
/\ = 4²-4.(-1).5
/\ = 16+20
/\ = 36
Yv = -/\ / 4a
Yv = -36/4.(-1)
Yv = -36/-4
Yv = 9
Answer:
The value of the 2 is two-thousand
Step-by-step explanation:
Answer:11
Step-by-step explanation:
Boys : girls=7:1
Sum of ratio=7+1=8
Let them number of girls be y
Then they number of boys=y+66
Total number of pupils=y+y+66
Total number of pupils=2y+66
Number of girls=(girls ratio)/(sum of ratio) x (total number of pupils)
y=1/8 x (2y+66)
Cross multiply
y x 8=2y + 66
8y=2y + 66
Collect like terms
8y-2y=66
6y=66
Divide both sides by 6
6y/6=66/6
y=11
The number of girls is 11
