4. Xavier has a rectangular piece of card. He cuts off the four corners. What do the angles of the remaining shape add up to?

1080°

Step-by-step explanation:

the rectangle has 4 sides and 4 angles of 90° angles; when the corners are cut, there are now 8 sides and 8 angles, aka an octogon, which has the total angles of 1080°

42 inches then 10 1/2 deep

i think it's ф or x=6,-6

step-by-step explanation:

-x^2=-36

x^2=-36

ф

or

if you mean by : -(x^2)=-36

it'll be: x^2=36

x=6,x=-6

hope it'll ! have a good day!

you for asking!