A high-speed train passes through a 5.4 km long tunnel completely in 1 minute 7.68 seconds.
1 answer:
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Answer:
-13x+10
Step-by-step explanation:
(4x+5)(x-2)
Multiply each term in the first parenthesis by each term in the second (foil)
Step 1: Expand it by writing out each multiplication. I added a picture showing which order to do it. (go in order of green, red, blue, yellow.) (you can remember this as first, outside, inside, last.)
When you expand it'll look like: 4x⋅x+4x⋅-2-5x-5⋅-2
Step 2: Calculate product
4x⋅x+4x⋅-2-5x-5⋅-2 (for the 4x⋅x it would be written like )
+4x⋅-2-5x-5⋅-2
+4x⋅-2-5x-5⋅-2 (4x⋅-2 becomes -8x) (multiply 4x times -2)
-8x-5x-5⋅-2
-8x-5x-5⋅-2 (-5⋅-2 becomes +10) (multiply -5 times -2)
-8x-5x+10
Step 3: collect like terms
-8x-5x+10 (-8x-5x becomes -13x) (-8x times -5x)
-13x+10 is the most simplified so it should be your final answer
