## Prealgebra (7th Edition)

$x=20$
"Twice" means multiplied by 2. The term preceding "subtracted from" is the subtrahend. The comma tells us the "twice" applies to "a number" rather than to the difference. $60-2x=20$ $\longrightarrow$addition property $60-2x-60=20-60$ $\longrightarrow$combine like terms $-2x=-40$ $\longrightarrow$multiplication property $-2x\div-2=-40\div-2$ $\longrightarrow$divide $x=20$