math subject
posted by jam on .
make (a) the subject
2a+squareroot of 2a^2=10

2a + sqrt(2a^2) = 10,
Isolate the radical:
2a  10 = sqrt(2a^2),
Square both sides:
4a^2  40a + 100 = 2a^2,
4a^2  2a^2  40a + 100 = 0,
2a^2  40a + 100 = 0,
Divide both sides by 2:
a^2  20a + 50 = 0,
Solve for a using the quadratic formula:
a = (20 + sqrt(400  200) / 2,
(20 + sqrt(100 * 2) / 2,
a = (20 + 10 * sqrt(2)) / 2,
a = 10 + 5 * sqrt(2),
a = 10 + 7.07,
a = 17,07, and 2.93.