36.
2x + 6 = -4 /:2
x + 3 = -2
x = -2 -3
x = -5
2(-5) + 6 = -4
-10 + 6 = -4
odpowiedź:: B. -5
37.
a) 2x + 7 = ...
x = 5
2×5 + 7 = ...
10 + 7 = 17
... = 17
b)
[tex] \frac{9 - x}{4} = ...4 \\ 9 - x = ...[/tex]
x = 5
9 - 5 = 4
... = 4
38.
a)
[tex]2 \frac{2}{3} + x = 12 \\ \frac{8}{3} + x = \frac{36}{3} \\ x = \frac{36}{3} - \frac{8}{3} \\ x = \frac{28}{3} \\ x = 9 \frac{1}{3} [/tex]
b)
[tex]4x = 13 \div 4 \\ x = \frac{13}{4} \\ x = 3 \frac{1}{4} \\ x = 3.25[/tex]
c)
[tex] \frac{1}{6} x = - 4 \times 6 \\ x = - 24[/tex]
d)
[tex]5 - x = - 4 \\ - x = - 4 - 5 \\ - x = - 9 \times - 1 \\ x = 9[/tex]
39.
[tex]x + 23 = 15 \\ x = 15 - 23 \\ x = - 8[/tex]
[tex]x - 6 = 2 \\ \times = 2 + 6 \\ x = 8[/tex]
[tex] \frac{1}{2} x = - 8 \times 2 \\ x = - 16[/tex]
40.
[tex]x + 4 = - 2 \\ x = - 2 - 4 \\ x = - 6[/tex]
[tex]a. \\ 3x = - 6 \div 3 \\ x = - 2[/tex]
[tex]b. \\ 2x = - 12 \div 2 \\ x = - 6[/tex]
[tex]c. \\ 2x = 12 \div 2 \\ x = 6[/tex]
[tex]d. \\ \frac{1}{3} x = - 6 \times 3 \\ x = - 18[/tex]
Odpowiedź: A
41.
[tex]2x - 3 = 47 \\ 2x = 47 + 3 \\ 2x = 50 \div 2 \\ x = 25[/tex]
42.
1.
[tex]p = \frac{a \times h}{2} [/tex]
[tex]p = \frac{2x\times 4}{2} \\ p = \frac{8x}{2} \\ p = 4x[/tex]
4x = 2
Prawda
2. a = 20
[tex]p = \frac{10 \times 4}{2} \\ p = \frac{40}{2} \\ p = 20[/tex]
Prawda
1. Prawda
2. Prawda
43.
a) 16 + 5x = 41
5x = 41 - 16
5x = 25 /:5
x = 5
b) 4y - 6,4 = - 25,6
4y = -25,6 + 6,4
4y = -19,2 /:4
y = -4,8
c) 8x - 5 - 6x = 7
8x - 6x = 7 + 5
2x = 12 /:2
x = 6
