Math formula or just some help

[BTC_GHD]

I need a formula for this problem or just some help


Jina's Coffee Shop makes a blend that is a mixture of two types of coffee. Type A coffee costs Jina $4.05 per pound, and type B coffee costs $5.15 per pound. This month, Jina made 178 pounds of the blend, for a total cost of $811.10 . How many pounds of type B coffee did she use?

[BTC_GHD]

Never mind got it down

[dagi]

xA + xB = 178
xA*4.05 + xB*5.15 = 811.1
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xB = 178 - xA
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xA*4.05 + (178 - xA)*5.15 = 811.1
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bla bla bla
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xA = 96
xB = 82