Arestaurant bill comes to $28.35. find the total cost if the tax is 6.25% and a 20% tip is left on the amount before tax.

The question is asking for the total cost after a tip and tax is added to the subtotal. In this case, you will be multiplying those percentages by the subtotal and adding them together to get your answer.
Sub-total = Original pricing ($28.35)
$28.35 * 6.25% = $30.14
Multiply the total by the tip to get the final answer 
$30.14 * 20% = $36.17
Basically, you are multiplying the percentages by the number to find out how much of it that percentage is. Then you are adding that to the sub-total to find the total. You do this twice when it asks for these.

Intersecting secant-tangent theorem states that if a tangent segment and a secant segment are drawn to a circle from an exterior point, then the square of the measure of the tangent segment is equal to the product of the measures of the secant segment and its external secant segment.so to break it down: 1. pq acts as the tangent and ps as the secant with an intersection at p.sr = 21rp = 3x + 3pq = 4x + 4following to equation: tangent squared = the two segments multiplied by each otherso (4x + 4) ^ 2 = (3x + 3) • (21) simplifies to 16x^2 - 31x - 47 = 0 or (16x - 47)(x + 1) x = -1 or x = 47/162. pq acts as the tangent and ps as the secant with an intersection at p (again! )sr = 16rp = xpq = 15(15) ^ 2 = 16 • x225 = 16xx = 225/163. the interesting chords are proportional to each other so a ratio is possible to set up: ap dp 10 3 + x = = —— = pc pb 8 xcross multiple to get 10x = (3 + x)(8)x = 12