Question

am nevoie urgent va rog!!​

Answer 1

a) 13/9 + 5/6 × 8/3 = 13/9 + 5/3 × 4/3 = 13/9 + 20/9 = ( 13 + 20 )/9 = 33/9 = 11/3

b) 21/5 - 1/10 : 1/2 = 21/5 - 1/10 × 2 = 21/5 - 1/5 = ( 21 - 1 )/5 = 20/5 = 4

c) 33/16 - 5/16 : 5/8 - 3/4 × 3/4 = 33/16 - 5/16 × 8/5 - 9/16 = 33/16 - 1/2 - 9/16 = ( 33 - 9 )/16 = 24/16 - 1/2 = 3/2 - 1/2 = ( 3 - 1 )/2 = 2/2 = 1

d) 17/45 × 15/34 + 1/2 + 1/15 × 5 = 1/3 × 1/2 + 1/2 + 1/3 = 1/6 + 1/2 + 1/3 = ( 1 + 3 + 2 )/6 = 6/6 = 1

e) 1/2 × 2/3 + 4/5 × 5/6 = 1/3 + 2/3 = ( 1 + 2 )/3 = 3/3 = 1

f) 99/100 : 11/10 + 17/40 : 17/4 = 99/100 × 10/11 + 17/40 × 4/17 = 9/10 + 1/10 = ( 9 + 1 )/10 = 10/10 = 1

g) 5/18 + 14/9 : 7/3 + 1/2 : 9 = 5/18 + 14/9 × 3/7 + 1/2 × 1/9 = 5/18 + 2/9 × 3 + 1/2 × 1/9 = 5/18 + 2/3 + 1/18 = ( 5 + 1 )/18 = 6/18 = 1/3 + 2/3 = ( 1 + 2 )/3 = 3/3 = 1

h) x/x+1 + x/x²+x = x/x+1

x² + x = factor comun x( x + 1 ) = x/x+1 + 1/x+1 = x+1/x+1 = 1

i) 1/2a+1 × 4a+2/3 =

4a + 2 =  factor comun = 2( 2a + 1 ) = 1/2a+1 ×2(2a+1)/3

2a + 1  cu 2a + 1 se simplifică = 2/3