Answer:
Option d) x = 25
Step-by-step explanation:
we have
Solve for x
Subtract 4 both sides
squared both sides
Adds 9 both sides
<u><em>Verify </em></u>
1) For x=25
----> is true
therefore
x=25 is a solution
2) For x=-7
The radicand cannot be a negative number
therefore
x=-7 is not a solution
Answer:
The total number of pupils and their teachers = 530
Step-by-step explanation:
No. of girls in the school = 280
The ratio boys to girls is 3:4 and that of teachers to girls is 1:7
∴ The ratio boys to girls is 3x : 4x where, 4x = 280
and The ratio of teachers to girls is x : 7x where, 7x = 280
4x = 280
= x
70 = x
So, the no. of girls in the school = 4x = 4(70) = 280 and the no. of boys in the school = 3x = 3(70) = 210
7x = 280
= x
40 = x
So, the no. of girls in the school = 7x = 7(40) = 280 and the no. of teachers in the school = x = 40
∴ The total number of pupils and their teachers = 280 + 210 + 40
= 530