$60,36 ÷ x + 43,14 ÷ x = 45\\⇒(60,36+43,14) ÷x=45\\ ⇒103,5÷x=45\\⇒x=103,5÷45 \\ ⇒x=2,3\\\text{______________________________}\\x × 12,35 + x × 12,65 = 875\\ ⇒x×(12,35+12,65)=875\\ ⇒x×25=875\\ ⇒x=875÷25\\ ⇒x=35\\\text{______________________________}\\102 ÷ x - 7,5 ÷ x = 27 \\⇒(102-7,5)÷x=27\\⇒94,5÷x=27 \\⇒x=3,5\\\text{______________________________}\\x + x × 2,7 + x × 6,3 = 120\\⇒x×(1+2,7+6,3)=120\\⇒x×10=120\\⇒x=120÷10\\⇒x=12$
Xin hay nhất !