1. $510 + (-401) = 510 - 401 = 109$
$256 + (-140) = 256 - 140 = 116$
$(-14) + (-14) = -28$
$(-213) + 200 = -13$
2. $(-24) + 17 + (-36) + 43 = (-24 - 36) + (17 + 43) = -60 + 60 = 0$
$17 + (-21) + 4 = (17 + 4) - 21 = 21 - 21 = 0$
$(-50) + (-14) + (-6) = -70$
$(-12) + (-18) + 12 = (-12 + 12) - 18 = 0 - 18 = -18$
3. $21 - (-41) + (-30) - (-70) = 21 + 41 - 30 + 70 = 132 - 30 = 102$
$(-7) + 25 - (-8) + (-12) - 5 = -7 + 25 + 8 - 12 - 5 = 33 - 24 = 9$
$(-20) - (-30) + 20 + (-30) = -20 + 30 + 20 - 30 = 0$
1. $20 + x = -36 \Rightarrow x = -36 - 20 = -56$
2. $x + (-12) = -2 \Rightarrow x = -2 + 12 = 10$
3. $(-12) + x = 6 \Rightarrow x = 6 + 12 = 18$
4. $x - 17 = 4 \Rightarrow x = 4 + 17 = 21$
5. $(-226) + x = 24 \Rightarrow x = 24 + 226 = 250$
6. $45 - x = (-45) \Rightarrow -x = -45 - 45 = -90 \Rightarrow x = 90$
7. $(-122) - x = (-108) \Rightarrow -x = -108 + 122 = 14 \Rightarrow x = -14$
8. $(-35) + x = (-40) \Rightarrow x = -40 + 35 = -5$
9. $(-16) + x + (-34) = (-50) \Rightarrow x - 50 = -50 \Rightarrow x = 0$
10. $x + 223 + (-24) = 0 \Rightarrow x + 199 = 0 \Rightarrow x = -199$
11. $(-5) + x + (-15) = 60 \Rightarrow x - 20 = 60 \Rightarrow x = 80$
12. $525 - x = (-25) \Rightarrow -x = -25 - 525 = -550 \Rightarrow x = 550$
1. $A = a + 25 + 17 - b - 26 - a + b - 25$
$A = (a - a) + (-b + b) + (25 + 17 - 26 - 25)$
$A = 0 + 0 + (-9) = -9$
2. $B = 12 + a - 10 - a - 25 + 40 - a + 8 + a$
$B = (a - a - a + a) + (12 - 10 - 25 + 40 + 8)$
$B = 0 + 25 = 25$
3. $C = a - b - 4 - [66 - a + 22 + 18 - b] - 50 - a$
$C = a - b - 4 - 106 + a - b - 50 - a$
$C = (a + a - a) + (-b - b) + (-4 - 106 - 50)$
$C = a - 2b - 160$
4. $D = a + b - c - c + b - a - b + c$
$D = (a - a) + (b + b - b) + (-c - c + c)$
$D = 0 + b - c = b - c$
5. $E = a - b - c + c - a + b + c$
$E = (a - a) + (-b + b) + (-c + c + c)$
$E = 0 + 0 + c = c$
6. $F = a + b + c - a + b - c + a - b - c - a - b + c$
$F = (a - a + a - a) + (b + b - b - b) + (c - c - c + c)$
$F = 0 + 0 + 0 = 0$
جد العدد الصحيح النسبي x
1. $(-10) - (25 + x) = (-14)$
$-10 - 25 - x = -14$
$-35 - x = -14$
$-x = 21$
$x = -21$
2. $(-26) - (-x - 30) = 8$
$-26 + x + 30 = 8$
$x + 4 = 8$
$x = 4$
3. $60 + (-56 - x) = 4$
$60 - 56 - x = 4$
$4 - x = 4$
$-x = 0$
$x = 0$
4. $(-20) - (-15 - x) = 14$
$-20 + 15 + x = 14$
$-5 + x = 14$
$x = 19$
نعتبر العبارتين التاليتين حيث a و b عددان صحيحان نسبيان:
1) بسط العبارتين G و H
2) احسب قيمة G و H عندما a = -2 و b = 3
3) احسب G + H و G - H
1) تبسيط العبارة G:
$G = (2+ a - 3-b + 5) + ( a + 2-b - 7) + (-a + b - 8)$
$G = 2 + a - 3 - b + 5 - a - 2+ b + 7 - a + b - 8$
$G =1 -a + b $
تبسيط العبارة H:
$H = -(3-a - b + 4) + (2-a + 3+b - 1) - (-a - 2 + b + 6)$
$H = -3 + a + b - 4 + 2 - a + 3 + b - 1 + a + 2 -b - 6$
$H = -7 + a + b $
2) حساب G و H عندما a = -2 و b = 3:
$G = 1 -a + b = 1 - (-2) +3 = 1+3+3= 7$
$H = -7 + a + b= -7 +(-2) +3 = -7 -2 +3 = -6$
3) حساب G + H و G - H:
$G + H = (1 -a + b) + (-7 + a + b) = 1 - a + b - 7 + a + b = -6 + 2b$
$G - H = (1 -a + b) - (-7 + a + b) = 1 - a + b + 7 - a - b = 8 -2a$