Question

9) Calcule o valor das seguintes equaçoes:

A) 7y = 5y -24

B) 3 (x-1) = x + 11

C) x / 2 - x/3 = 1


12) Aplicando os produtos notaveis calcule:

A) (3x+2)^2
B) (2y - 1)^2
C) (5b+2) (5b - 2)
D) (1/2 x -3)^2

Answer 1

(9)
A) 7y = 5y -24
    7y-5y=-24
     2y=-24
      y=$\frac{-24}{2}$
    y= -12

B) 3 (x-1) = x + 11
3x-3=x+11
3x-x=11+3
2x=14
x=$\frac{14}{2}$
x=7

C) $\frac{x}{2} - \frac{x}{3} =1$
$\frac{3x-2x}{6} =1$
$\frac{x}{6} =1$
x=6*1
x=6

(12)

A) (3x+2)²=>  (a + b)²=a²+2ab+b²  => 9x+12x+4 => 21x+4
  
B) (2y - 1)² => (a - b)²= a²-2ab+b² =>  4y-4y+1 => 1

C) (5b+2) (5b - 2) => (a+b)*(a-b)= a²+b² => (a + b)²+(a - b)² => 25b+20b+4+25b-20b+4 ==>  50b+8

D) (1/2x -3)²=>(a - b)²= a²-2ab+b² => 1/4x-3+9 =>1/4x+6