let's use x as an unknown variable. you know that this amount was twice what she spent. this statement means the amount is equal to 2x. however, the amount is also 12 dollars less. so, the equation would now become 2x-12. lastly, you know that the amount she spent on jeans was 36 dollars so the equation would equal 36 dollars: 2x-12=36 hope this !
½ r² ∅
the area of a sector of a circle is ½ r² ∅, where r is the radius and ∅ the angle in radians subtended by the arc at the centre of the circle. so in the below diagram, the shaded area is equal to ½ r² ∅ .
b. saturn is 10 times the equatorial radius of the earth.
that would be (6 * 10^4) / (6 * 10^3)
= 1 * 10^(4-3)