What should be subtracted from −9/16 so as to get 7/12 ? ( Class 7 )
Answers
Answer:
Solve the equation -3/4-x=-7/12, where x is the number you're looking for. Change this to 3/4+x=7/12. This was done by multiplying the whole equation through by -1. So for now there are no minus signs. The common denominator is 3×4=12, and 3/4=9/12. Multiply 3/4 by 3/3 to get the 9/12. Now to isolate the x, subtract 9/12 from both sides of 9/12+x=7/12, remembering to add numbers to numbers and letters to letters. You get 9/12-9/12+x=7/12-9/12, x=-2/12, x=-1/6 after reducing.
Another way: -3/4-x=-7/12. Write this as -3/4+(-x)=-7/12 to avoid confusion. The common denominator is 12. To get rid of the fractions and the minus signs, too, let's multiply both sides by -12: -12×(-3/4)+(-12)×(-x)=(-12)×(-7/12). Then cancelling the denominators, get (-3)×(-3)-12×(-x)=(-1)×(-7) from which 9+12x=7, 12x=7-9, 12x=-2, x=-2/12=-1/6.
Let's check this. Subtract -1/6 from -3/4: -3/4 take away -1/6 in math symbols is -3/4-(-1/6)=-3/4+1/6=-9/12+2/12=-7/12. So it works. Your number is -1/6.