All you do is solve for z. So 8z-13=7. To solve for a variable you have to do the opposite to cancel out the numbers on each side. First you add 13 over to 7 to cancel out 13 on the z side. So 8z=20 is what you have left. Then you divide 8 on both sides to cancel out 8 on the z side. what you are left with is z=2.5. Lastly you plug and check. 8(2.5) - 13 = 7, 20-13=7. And thats correct so z is 2.5.
Answer:
-4 or -3
Step-by-step explanation:
Calculate the determinant:
D = b^2 - 4ac = 49 - 48 = 1
Apply the formula:
x = (-b +- sqrt(D))/2a = (-7 +- 1)/2 = -4 or -3
Your answer is 4 radical 2.
