simplify 7/(25z^3y)-1/(35z^2y)
Let's sum the fractions: 725z3y -135z2y
ⓘ To add fractions, put them over the same denominator, then add the numerators: 725z3y -135z2y = 7·35z2y -1·25z3y25z3y·35z2y
7·35z2y -1·25z3y25z3y·35z2y
ⓘ Multiplications are done before additions and subtractions: 7·35 = 7·(30 + 5) = 7·30 + 7·5 = 210 + 35 = 245, 1·25z3y = 25z3y■Multiplying powers with the same base adds the exponents: z3·y·z2·y = z5y2
ⅰ 25·35 = (20 + 5)·35 = 20·35 + 5·35 = 700 + 175 = 875
245z2y -25z3y875z5y2
ⓘ A fraction is simplified by dividing the numerator and the denominator by the same number: 245z2y -25z3y875z5y2 = 49z2y -5z3y175z5y2
49z2y -5z3y175z5y2
ⓘ What the terms have in common is factored out, so that the fraction can be simplified: 49z2y -5z3y175z5y2 = yz2·(49 -5z)175z5y2
yz2·(49 -5z)175z5y2
We simplify the fraction: yy2 by the common factor: y to get the new quotient: 1y
We simplify the fraction: z2z5 by the common factor: z2 to get the new quotient: 1z3
49 -5z175·z3y
▶Result:   49 -5z175yz3