Use the square root property to solve the equation.
x^2 = 81
2007-05-13 09:58:12 · 8 answers · asked by swtsabre 1 in Science & Mathematics ➔ Mathematics
To figure this out, we must square root both sides.
So the sqrt (x^2) = sqrt (81)
x = + or - 9
Therefore x = 9 or x = -9
Another way to think of this is what two identical numbers when multiplied together will give you 81. We know that 9 times 9 is 81, so 9 is one possible solution, but we can also use - 9 x (-9) because two negatives will make a positive, giving you 81.
2007-05-13 10:02:25 · answer #1 · answered by Icobes 2 · 1⤊ 0⤋
Take the square root of both sides. The square root of x^2 is x. and the square root of 81 is +/-9. So, x= +/-9
2007-05-13 10:04:18 · answer #2 · answered by Baysoc23 5 · 0⤊ 0⤋
what you do is you square root both sides
the square root of x^2 is x and the sqquare root of 81 is 9 or -9 there fore x=9,-9
2007-05-13 10:06:06 · answer #3 · answered by Anonymous · 0⤊ 0⤋
x = + 9 or - 9
The square of 9 is 9 x 9 or -9 x -9
9 x 9 = 81
-9 x -9 = 81
2007-05-13 10:06:01 · answer #4 · answered by Lairbit 3 · 0⤊ 0⤋
x= square root of 81
x=9, -9
2007-05-13 10:05:17 · answer #5 · answered by icemoon 2 · 0⤊ 0⤋
x ^ 2 = 81
x = +ve or -ve sqr(81 )
= 9 and -9
s.s = { 9 , - 9 }
2007-05-13 10:04:14 · answer #6 · answered by muhamed a 4 · 0⤊ 0⤋
x = ±√81
x = ± 9
2007-05-13 10:06:29 · answer #7 · answered by Como 7 · 0⤊ 0⤋
x^2 = 81
x=9or-9 answer
2007-05-13 10:03:28 · answer #8 · answered by Anonymous · 0⤊ 0⤋