Question

Va rog am nevoie urgent
Ps:daca nu se vede poza intrati pe ea
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Answer 1

a)

$| \frac{1}{2} x - 2.5 | = |7 \frac{1}{2} - \frac{3}{4} x| \\ | \frac{1}{2} x - \frac{5}{2} | = | \frac{15}{2} - \frac{3}{4} x |$

CAZUL I

$\frac{1}{2}x - \frac{5}{2} = \frac{15}{2} - \frac{3}{4} x \\ 2x - 10 = 30 - 3x \\ 2x + 3x = 30 + 10 \\ 5x = 40 \\ x = \frac{40}{5} = 8$

CAZUL II

$\frac{1}{2} x - \frac{5}{2} = - ( \frac{15}{2} - \frac{3}{4} x) \\ \frac{1}{2} x - \frac{5}{2} = - \frac{15}{2} + \frac{3}{4} x \\ 2x - 10 = - 30 + 3x \\ 2x - 3x = - 30 + 10 \\ - x = - 20 \\ x = 20$

deci S= (8, 20)

b)

2x-1/5 =7 =>înmulțim ambele parti ale ecuației cu 5

2x-1=35

2x=35+1

2x=36

x=36/2

x=18

c)

(2/3)^x ÷ (2/3)^3=16/81 ×(2/3)^5

(2/3)^x-3= (2/3)^4 × (2/3)^5

(2/3)^x-3=(2/3)^9

x-3=9

x=9+3

x=12

d)

3+2/5 ×(3x-1 /8 +5x+1 /4)=x-1 /2 +1/3 ×7x+3 /2

3+ 3x-1 /20 + 5x+1 /10= x-1 /2 +7x+3 /6

(înmulțim ambele părți ale ecuației cu 60)

180+3(3x-1)+6(5x+1)=30(x-1)+10(7x+3)

180+9x-3+30x+6=30x-30+70x+30

180-3+6+30=-9x-30x+30x+70x

-183=-61x

183=61x

x= 183/61

x=3