86 7. оперирование понятием модуль числа найдите значение выражения 1) |3-4x|+|-y| при x=2.1 и y=0.4 2) |1.2-3x|-|y| при x=0.2 и y-0.6 3) 2|x|+|1-3x| при x=1,2 4) |4-5x|-3|x| при x=1.7 5) 7|-x|-4|3y-3.4| при х=-2 и у=0,8 6)3|x-1|-2|3-y при х=0,7 и у=1,7

1) |3-4x| + |-y| = |3-4*2.1| + |-0.4| = |3-8.4| + 0.4 =  |-5.4| + 0.4 = 5.4 + 0.4 = 5.8
2) |1.2-3x| - |y| = |1.2-3*0.2| - |-0.6| = |1.2-0.6| - 0.6 = 0.6 - 0.6 = 0
3) 2|x| + |1-3x| = 2|1.2| + |1-3*1.2| = 2*1.2 + |1-3.6| = 2.4 + |-2.6| = 2.4+2.6 = 5   
4) |4-5x| - 3|x| = |4-5*1.7| - 3|1.7| = |4-8.5|-3*1.7 = |-4.5| - 5.1 = 4.5 - 5.1 = -0.6
5) 7|-x|-4|3y-3.4| = 7|2| - 4|3*0.8-3.4| = 7*2 - 4|2.4-3.4| = 14 - 4|-1| = 14 - 4 = 10
6)3|x-1|-2|3-y| = 3|0.7-1|-2|3-1.7| = 3|-0.3|-2|1.3| = 3*0.3-2*1.3 = 0.9 - 2.6 = -1.7