Hello!
The answer would be d = 10. Solve it like this. (v v v)
10 * 0 + 4 * d = 40 ---> 0 + 4 * 10 = 40
0 + 40 = 40
40 = 40
Hope this helps! ☺♥
If 21 is added to (+ 21) a number (x) the result (=) is 40 less than (- 40) twice the number (2x)
x + 21 = 2x - 40 Add 40 to both sides
x + 61 = 2x Subtract x from both sides
61 = x Switch the sides to make it easier to read
x = 61
Consider the number of the adult tickets is x
X+2x=276
3x=276
X=92
So the student tickets is =184
What ever solution is left over after solved
