book Maths Puzzle Numerical Ability

i want to ask what is the answer of the following;
1.4y-{13x-(14y-2x}
2.5y-{18x-(5y+12x}
3.-{8x-[14y-(5-6x)-2]}
4.-4(x-3y)-(3x+5y)-(6-8y)

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book Other Question

If I need to find the opposite of the expression 7x + 3x. Mika leaves Boston for Baltimore at 10:00 A.M., traveling at
45mi/h. One hour later, Hiroko leaves Baltimore for Boston on the same route, traveling at 50mi/h. If the two cities are 425 mi apart, when will Mika and Hiroko meet?