Let a, b, c and d all be real numbers and let x, y and z be variables. What is the solution (solve for x) to the equation a(x+y) + bz + c = d and state any restrictions (you cannot divide by zero).
I'm lost for this... Can someone help me?
just do what you always do. It does not matter whether the symbols are variables or constants.
a(x+y) + bz + c = d
ax + ay = d-bz-c
ax = d-ay-bz-c
x = (d-ay-bz-c)/a
Clearly, a cannot be zero. Otherwise, all's fair in love and algebra.