quadratic formula:
x = <u>-b ± √(b² - 4ac)</u>
2a
7x² - x = 7
subtract 7 from both sides:
7x² - x - 7 = 0
plug values into the quadratic formula:
x = <u>-(-1) ± √((-1)²- 4(7)(-7))</u>
2(7)
simplify:
x = <u>1 ± √(197)</u>
14
Answer:
x = 10
Step-by-step explanation:
Solve for x:
2 (x + 2) - 7 + x = 27
2 (x + 2) = 2 x + 4:
2 x + 4 + x - 7 = 27
Grouping like terms, 2 x + x - 7 + 4 = (2 x + x) + (4 - 7):
(2 x + x) + (4 - 7) = 27
2 x + x = 3 x:
3 x + (4 - 7) = 27
4 - 7 = -3:
3 x + -3 = 27
Add 3 to both sides:
3 x + (3 - 3) = 3 + 27
3 - 3 = 0:
3 x = 27 + 3
27 + 3 = 30:
3 x = 30
Divide both sides of 3 x = 30 by 3:
(3 x)/3 = 30/3
3/3 = 1:
x = 30/3
The gcd of 30 and 3 is 3, so 30/3 = (3×10)/(3×1) = 3/3×10 = 10:
Answer: x = 10
