What element is located at b^31 -35 -1 8 65

is an element of the given 3x5 matrix B.  It is located on the third row and first column, which is therefore -1.

Abit confused about what you mean, but i think you might be referring to slope intercept form: y = mx + bin that case b, or the y intercept is already given.(0,-1)find the slope by using the formulay2 - y1/x2 - x1the final slope will be 4/2, equivalent to 2.now your equation should look like thisy = 4/2x -1sorry if this didn’t you out!

Element 17 is chlorine it is a group 7 element(halogen) and belongs to period 3 of the periodic table