Perform the indicated operation. (-9 + 21) - (-12 + 4) =
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Answer:
The merchant buys 30 shirts originally.
Step-by-step explanation:
Let us assume that the merchant bought x numbers of shirts in $120.
So, the cost for each shirt is $.
Now, if the cost for each shirt is reduced by 1$, then he would have bought 10 shirts more i.e. (x + 10) shirts in $120.
So, we can write the following equation as
⇒(120 - x)(x + 10) = 120x
⇒ 120x - 10x + 1200 - x² = 120x
⇒ x² +10x - 1200 = 0
⇒ x² + 40x - 30x - 1200 = 0
⇒(x + 40)(x - 30) = 0
⇒ x = - 40 or x = 30
But x can not be negative.
Hence, the merchant buys 30 shirts originally. (Answer)
<h3>Answer:</h3>
- ABDC = 6 in²
- AABD = 8 in²
- AABC = 14 in²
A diagram can be helpful.
When triangles have the same altitude, their areas are proportional to their base lengths.
The altitude from D to line BC is the same for triangles BDC and EDC. The base lengths of these triangles have the ratio ...
... BC : EC = (1+5) : 5 = 6 : 5
so ABDC will be 6/5 times AEDC.
... ABDC = (6/5)×(5 in²)
... ABDC = 6 in²
_____
The altitude from B to line AC is the same for triangles BDC and BDA, so their areas are proportional to their base lengths. That is ...
... AABD : ABDC = AD : DC = 4 : 3
so AABD will be 4/3 times ABDC.
... AABD = (4/3)×(6 in²)
... AABD = 8 in²
_____
Of course, AABC is the sum of the areas of the triangles that make it up:
... AABC = AABD + ABDC = 8 in² + 6 in²
... AABC = 14 in²