Let the 1st number be x; 2nd number be y; 3rd number be z.
x + y + z = 79
x = number we are looking for.
y = x * 5 ==> 5 times the first
z = x + 16 ==> 16 more than the first
Therefor,
x + (x * 5) + (x+16) = 79
1st step, multiply the 2nd number: x * 5 = 5x
x + 5x + x + 16 = 79
Add all like numbers:
7x + 16 = 79
To get x, transfer 16 to the other side and change its sign from positive to negative.
7x = 79 - 16
7x = 63
To get x, divide both sides by 7
7x/7 = 63/7
x = 9
To check. Substitute x by 9.
x + (x * 5) + (x+16) = 79
9 + (9 * 5) + (9 + 16) = 79
9 + 45 + 25 = 79
79 = 79 equal. value of x is correct.
A triangular prism which has 5 faces (two triangle and three rectangle)
we are given

we can see that
numerator is

and denominator is

We always put coefficient of numerator inside box
we can see that coefficient of numerators are 3 , -4 and 9
and in the left side , we put value of x after putting denominator =0


so, left side will be 2
so, option-D..................Answer
The answer is 1 because you have to Substitute Two form X then it would just be Then substitute 2 form 1 and you would get 1