why the Moho is located at a greater depth under high mountain ranges than under the deep ocean basins.

As the crust is thicker and less dense in mountains ranges.

Explanation:

Moho is a boundary between the earth's crust and mantle and is a depth of 8 km at the surface and 32 km beneath the continents. The lower density material beneath the earth's crust is called the lithospheric crust and the higher density of material located below this layer is the mantel. This Moho is also called moho-discontinuity and here the seismic waves change their velocity before reaching the surface.

Nigeria and south africa

343^x = 49^4-xx = 4-xx+x=42x = 4x = 4/2x = 2therefore x = 2