Question

determinati un numar daca 50 reprezinta : a) 25 % din el
b) 50% din el
c) 80 % din el
d ) 12.5 % din el
e) 160% din el
f) 250 % din el
g) 40 % din el
h) 2,5 % din el.

Answer 1

$a) \frac{25}{100} \times x = 50$

$\frac{1}{4} \times x = 50$

$\frac{x}{4} = 50$

$x = 4 \times 50$

$x = 200$

$b) \frac{50}{100} \times x = 50$

$\frac{1}{2} \times x = 50$

$\frac{x}{2} = 50$

$x = 2 \times 50$

$x = 100$

$c) \frac{80}{100} \times x = 50$

$\frac{4}{5} \times x = 50$

$\frac{4x}{5} = 50$

$4x = 5 \times 50$

$4x = 250$

$x = \frac{250}{4}$

$x = \frac{125}{2}$

$d) \frac{12.5}{100} \times x = 50$

$\frac{ \frac{125}{10} }{100} \times x = 50$

$\frac{125}{10} \times \frac{1}{100} \times x = 50$

$\frac{25}{10} \times \frac{1}{20} \times x = 50$

$\frac{5}{10} \times \frac{1}{4} \times x = 50$

$\frac{1}{2} \times \frac{1}{4} \times x = 50$

$\frac{x}{8} = 50$

$x = 8 \times 50$

$x = 400$

$e) \frac{160}{100} \times x = 50$

$\frac{16}{10} \times x = 50$

$\frac{8}{5} \times x = 50$

$\frac{8x}{5} = 50$

$8x = 5 \times 50$

$8x = 250$

$x = \frac{250}{8}$

$x = \frac{125}{4}$

$f) \frac{250}{100} \times x = 50$

$\frac{25}{10} \times x = 50$

$\frac{5}{2} \times x = 50$

$\frac{5x}{2} = 50$

$5x = 2 \times 50$

$5x = 100$

$x = \frac{100}{5}$

$x = 20$

$g) \frac{40}{100} \times x = 50$

$\frac{4}{10} \times x = 50$

$\frac{2}{5} \times x = 50$

$\frac{2x}{5} = 50$

$2x = 5 \times 50$

$2x = 250$

$x = \frac{250}{2}$

$x = 125$

$h) \frac{2.5}{100} \times x = 50$

$\frac{ \frac{25}{10} }{100} \times x = 50$

$\frac{25}{10} \times \frac{1}{100} \times x = 50$

$\frac{1}{10} \times \frac{1}{4} \times x = 50$

$\frac{x}{40} = 50$

$x = 40 \times 50$

$x = 2000$

Answer 2

a)x numărul
25%x=50
1/4×X=50
x=4×50
x=200
b)50%inseamna jumătate
jumătatea cui este 50?
x=100
c)80%x=50
8/10x=50
x=500/8
x=62,5
d)12,5%x=50
x=5000:12,5
x=400
e)160/100x=50
x=5000:160
x=500:16
x=31,25
f)250/100x=50
10/4x=50
x=200/10
x=20
g)40%x=50
40/100x=50
x=5000/40
x=500/4
x=125
h)2,5%x=50
2,5/100x=50
x=5000/2,5
x=2000