Answer:
x = 6 or x = -7
Step-by-step explanation:
Solve for x over the real numbers:
x^2 + x - 42 = 0
The left hand side factors into a product with two terms:
(x - 6) (x + 7) = 0
Split into two equations:
x - 6 = 0 or x + 7 = 0
Add 6 to both sides:
x = 6 or x + 7 = 0
Subtract 7 from both sides:
Answer: x = 6 or x = -7
The point of elimination is to have one variable so example
3x + 2y = 4
7X + 3y = 5
1) Try to find a way to have one variable
7(3x + 2y = 4) ----> 21x + 14y = 28
-3(7x+ 3y = 5) -----> -21x -9y = -15
2) add
0 + 5y = 13
3) solve for the last variable
5y = 13
y = 13/5 = 2 3/5 = 2.8
4) Subsitute the variable to get the other one
3x + 2(2.8) = 4
3x + 5.6 = 4
3x = -1.6
x = 0.533333333 (continue)
The intersection would be 0.53 with a line above the 3 and 2.8. (0.5333 , 2.8)
Hope you understand!!
Answer:
-199
Step-by-step explanation:
