Solve for x
x=300
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15x+4\left(1200-2x\right)=6900
Multiply both sides of the equation by 3.
15x+4800-8x=6900
Use the distributive property to multiply 4 by 1200-2x.
7x+4800=6900
Combine 15x and -8x to get 7x.
7x=6900-4800
Subtract 4800 from both sides.
7x=2100
Subtract 4800 from 6900 to get 2100.
x=\frac{2100}{7}
Divide both sides by 7.
x=300
Divide 2100 by 7 to get 300.
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