彼はその難しい仕事を一人で請け合った。
He took on that difficult job by himself.
頼まれた修理を二つ返事で請け合ってしまった。
I readily agreed to take on the repair I was asked to do.
期限までに仕上げると請け合った以上、やり遂げるしかない。
Now that I've promised to finish it by the deadline, I have no choice but to see it through.