Question

4. Реши уравнения.
35 + 23 + х = 100
70 – a = 8 +9+2
а+ (45 – 30) = 75
x — (23 + 17) = 60
(30 – 15) +y= 80
х+ 12 = 50 – (15+5)​

Answer 1

$\displaystyle \tt 35+23+x=100\\\displaystyle \tt 58+x=100\\\displaystyle \tt x=100-58\\\displaystyle \tt \bold{x=42}$

$\displaystyle \tt 70-a=8+9+2\\\displaystyle \tt 70-a=19\\\displaystyle \tt -a=19-70\\\displaystyle \tt -a=-51\\\displaystyle \tt \bold{a=51}$

$\displaystyle \tt a+(45-30)=75\\\displaystyle \tt a+15=75\\\displaystyle \tt a=75-15\\\displaystyle \tt \bold{a=60}$

$\displaystyle \tt x-(23+17)=60\\\displaystyle \tt x-40=60\\\displaystyle \tt x=60+40\\\displaystyle \tt \bold{x=100}$

$\displaystyle \tt (30-15)+y=80\\\displaystyle \tt 15+y=80\\\displaystyle \tt y=80-15\\\displaystyle \tt \bold{y=65}$

$\displaystyle \tt x+12=50-(15+5)\\\displaystyle \tt x+12=50-20\\\displaystyle \tt x+12=30\\\displaystyle \tt x=30-12\\\displaystyle \tt \bold{x=18}$