Rozwiąż równanie. 1) x+(7+x) ______________=20 2

x+(7+x) ______________=20 |*2 2 x+7+x = 40 2x = 37 x = 18,5

1) x+(7+x) ---------------------- x+7+x 2x+7 --------------------------- 2)2x+7=20 ========================= 2x=20-7 2x=13 13/2=6,5 x=6,5

0,5x + 3,5 + 0,5x = 20 x +3,5 = 20 x = 16,5 lub x+(7+x) ______________=20 | *2 2 x+7+x = 40 |-7 2x = 33 x = 16,5