1) 6(r + 10) + 3(2r - 7) = - 45 2) 8t + 4(t - 2) = - 2 - 6 (2t + 9) 3) 9 − 2(x + 4) − 10(25 − x + 4) = 5 − 3x − 4(x + 1) 4) - {7x + [ - 4x + ( - 2 + 4x)] - (5x + 1)} = 0 5) - {4x - [ - 2x - (3x + 6)]} = 4 - { - x + (2x - 1)}.
1) 6(r + 10) + 3(2r - 7) = - 45 6r + 60 + 6r - 21 = - 45 12r = - 45 - 60 + 21 r = - 84 / 12 r = - 7
2) 8t + 4(t - 2) = - 2 - 6 (2t + 9) 8t + 4t - 8 = - 2 - 12t - 54 8t + 4t + 12t = - 2 + 8 - 54 24t = - 48 t = - 48 / 24 t = - 2
3) 9 − 2(x + 4) − 10(25 − x + 4) = 5 − 3x − 4(x + 1) 9 - 2x - 8 - 250 + 10x - 40 = 5 - 3x - 4x - 4 - 2x + 10x + 3x + 4x = 5 - 9 + 8 + 250 + 40 - 4 15x = 290 x = 290 / 15 x = 19.
3
4) - {7x + [ - 4x + ( - 2 + 4x)] - (5x + 1)} = 0 - {7x + [ - 4x - 2 + 4x] - 5x - 1} = 0 - {7x - 2 - 5x - 1} = 0 - 7x + 2 + 5x + 1 = 0 - 2x = - 2 - 1 x = - 3 / - 2 x = 1.
5
5) - {4x - [ - 2x - (3x + 6)]} = 4 - { - x + (2x - 1)} - {4x - [ - 2x - 3x - 6]} = 4 - { - x + 2x - 1} - {4x + 2x + 3x + 6} = 4 + x - 2x + 1 - 4x - 2x - 3x - 6 = 4 + x - 2x + 1 - 4x - 2x - 3x - x + 2x = 4 + 6 + 1 - 8x = 11 x = 11 / - 8.