Question

99+450:к=108
60*а+40=800:2​

Answer 1

$1)99 + 450 \div k = 108 \\ 450 \div k = 108 - 99 \\ 450 \div k = 9 \\ k = 450 \div 9 \\ k = 50 \\ 2)60 \times a + 40 = 800 \div 2 \\ 60a + 40 = 400 \\ 60a = 400 - 40 \\ 60a = 360 \\ a = 360 \div 60 \\ a = 6$