Question

Ajutatima va rog.. Imi trebue pe miine.
Rezolvati ecuatiile:
a)5*(x+9)=135
b) 12*(x-5)=144
c)15*(18-x)=180
d)63 / (x-2)=7
e) 9*(2x+1)153
f) 14x+28x =588
Dau coroana si multe puncte ..........
AJUTORRRRRR

Answer 1

a) 5*(x+9)=135 5*x+5*9 =135 5x+45. =135 5x. =135-45 5x. =90 x=90:5 x=18 probă: 5*(18+9)=135, 5*27=135, 135=135. b) 12*(x-5)=144 12*x-12*5=144 12x-60. =144 12x. =144+60 12x. =204 x. =204:12 x. =17 probă: 12*(17-5)=144, 12*12=144, 144=144 c) 15*(18-x)=180 15*18-15*x=180 270-15x=180 15x=270-189 15x=90 x=90:15 x=6 probă: 15*(18-6)=189, 15*12=180, 180=180. d) 63:(x-2)=7 x-2=63:7 x-2=9 x=9+2 x=11 probă: 63:(11-2)=7, 63:9=7, 7=7. e) 9*(2x+1)=153 9*2x+9*1=153 18x+9=153 18x=153-9 18x=144 x=144:18 x=8 probă: 9*(2*8+1)=153, 9*17=153, 153=153. f) 14x+28x=588 42x=588 x=588:42 x=14 probă: 14*14+28*14=588, 196+392=588, 588=588. * ~înseamnă( înmulțire) !