Question

5. Calculați, folosind factorul comun:
a) 20.7+20-13+20-80
b) 238.15-7.238+2.238
c) 145+145 2+145-3+145.4
d) 2009+2009-2010-2009-2011
e) 2011-2010-2011 2009+2011
25.7+25².8+25³
g) 5-2³ +7.2³-2³
h) 26-3²-25-3² -2¹.3²
i) 21-11-21-11+21².11

Answer 1

b) 238.15-7.238+2.238 = 238 * (1 - 0.03 + 0.01) = 238 * 0.98 = 233.64
c) 145+145 2+145-3+145.4 = 145 * (1 + 1 + 1 - 0.02 + 1.004) = 145 * 3.984 = 580.72
d) 2009+2009-2010-2009-2011 = 2009 * (1 + 1 - 1 - 1 - 1) = 2009 * (-1) = -2009
e) 2011-2010-2011 2009+2011 = 2011 * (1 - 1 - 1 + 1) = 2011 * 0 = 0
25.7+25².8+25³ = 25 * (1.028 + 1 + 1) = 25 * 3.028 = 75.7
g) 5-2³ +7.2³-2³ = 2³ * (2.5 - 1 + 3.5 - 1) = 2³ * 2 = 16
h) 26-3²-25-3² -2¹.3² = 3² * (8.5 - 1 - 8.5 - 1 - 2) = 3² * (-4.5) = -40.5
i) 21-11-21-11+21².11 = 11 * (1.9 - 1 - 1.9 - 1 + 19) = 11 * 17.1 = 187.1