tomas orders a meal that costs $7.89. Lisa's meal costs $9.05. About how much is the combined cost of their meals?

$17

Step-by-step explanation:

This is a question on Estimation - which is a very important skill!

the first meal was $7.89, which is roughly $8the second meal was $9.05, which is roughly $9

yes because they have the same amount of green and blur marbles.

step-by-step explanation:

we have three similar triangles, because each has a right angle and shares an angle.   let's write the angles in order: opposite to short leg, long leg, hypotenuse.

cab similar to bad similar to cbd

or as ratios,

ca: ab: cb = ba: ad: bd = cb: bd: cd

we also know

ac = ad + cd

(ad+cd): ab: cb = ba: ad: bd = cb: bd: cd

(ad+cd)/cb=cb/cd

we have cb=6, ad=5 and seek x=cd.

we reject the negative root and conclude x=4

answer: 4