A. 5.00x-2.25x=5000 B.5.00x=5000 C.2.25x=5000 D.5.00x+2.25x=5000
To invent something, you have to have some material with which to invent.
Sand blasting equipment
Digital Equipment Corporation (DEC)
with material
TNT, dynamite
a chain with clothes and a staff to pull Captain Winter out.
invent something or take acting or singing lessons.
Jo Anderson helped to invent the reaper. This was a mechanical farming equipment that planted larger fields, which lessen the work of farm labors.
They took material and put it together.
she used old material
A summary involves deletion of less important details. You would not substitute or invent new material, because a summary is supposed to convey an accurate picture of the summarized material, not a revised version.
They did not invent new materials, but they engineered ways to make them work better, like the arch.