Решить уравнение. 24145+(х-519)=29003

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№ 329
98 * 3 = (100 - 2) * 3 = 100* 3 - 2 * 3 = 300 - 6 = 294
99 * 5 = (100 - 1) * 5 = 100 * 5 - 1 * 5 = 500 - 5 = 495
196 * 15 = (200 - 4) * 15 = 200* 15 - 4 * 15 = 3000 - 60 = 2940
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№ 331
в) неверно.
   Правильное решение:
   5 + 5 * 4 + 7 * 5 = 5 + 5*(4 + 7) = 5 + 5 * 11 = 5 + 55 = 60
г) верно.
   3*23-17*3+3*4 = 3(23-17 + 4) = 3*10 = 30
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№332
а) = 4(14 + 16) = 4 * 30 = 120
    = 18*(3 + 7) = 18 * 10 = 180
    = 7*(33+ 7) = 7 * 40 = 280
б) = 8*(68 -28) = 8 * 40 = 320
    = 74 *(16 - 15) = 74 * 1 = 74
   = 52 *( 33-31) = 52 * 2 = 104

A_n = 2-5*n 
a_n+1 = 2-5*(n+1) = 2-5*n - 5 = -3 - 5*n
d = a_n+1 - a_n = -3 - 5*n - (2 - 5*n) = -3-2 = -5
a1 = 2-5 = -3
S_60 = (2*a1 + 59*d)*30 = (-6-295)*30 = -9030