math
posted by jen .
2{[5(c4)+15][3(5c3)+1]}
Can someone help me to figure out this equation. I don't remember how to do this with the outside brackets

start with the innermost brackets and work outwards
2{[5(c4)+15][3(5c3)+1]}
= 2{[5c20+15][15c9+1]}
= 2{[5c5][15c8]}
= 2{5c515c+8]}
= 2{10c+3]}
= 20c + 6