Answer:
7
Step-by-step explanation:
2x^2 - 7x - 4 = 45
2x^2 - 7x - 49 = 0 : subtract 45 from both sides
Quadratic formula:
x = (7 ± sqrt(7^2 - 4*2*-49) ) / 4
x = (7 ± sqrt(49 - -392)) / 4
x = (7 ± sqrt(441)) / 4
x = (7 ± 21) / 4
x = (7 + 21) / 4 OR x = (7 - 21) / 4
x = 28 / 4 OR x = -14 / 4
x = 7 as it is the only positive answer
