Solve x/5 - x/2= 21. What is the value of x?
a) -70
b) -7
c) 7
d) 70
To solve for x, we can eliminate the denominators by multiplying the entire equation by 10 (which is the LCM of 5 and 2):
10(x/5) - 10(x/2) = 10(21)
2x - 5x = 210
-3x = 210
x = -210/3
Simplifying further, we get:
x = -70
Therefore, the value of x is -70.
The correct answer is a) -70.
To solve the equation x/5 - x/2 = 21, we need to find a common denominator for the fractions.
The common denominator for 5 and 2 is 10. So, we can rewrite the equation as:
(2x - 5x) / 10 = 21
Next, combine the terms on the left side of the equation:
-3x / 10 = 21
To isolate x, we need to get rid of the coefficient (-3/10) multiplying x. To do this, we can multiply both sides of the equation by the reciprocal of -3/10, which is -10/3:
(-10/3) * (-3x/10) = (-10/3) * 21
Simplifying both sides gives:
x = -10 * 7
Therefore, x = -70.
So, the value of x is a) -70.