The sales tax for an item was $8.40 and it cost $420 before tax. find the sales tax rate. write your answer as a percentage.

-14 is the answer

hope this : ))

"standard form:

3x2 + 14x − 10 = 0

solutions based on quadratic formula:

x1   = −14 − √ 142 − 4×3×(−10) /   2×3   = −14 − 2 × √ 79 /   6   ≈ −5.296

x2   = −14 + √ 142 − 4×3×(−10) /   2×3   = −14 + 2 × √ 79 /   6   ≈ 0.629

why are you giving so many marks make your marks less and make a question list so that i can understand your question very nicely

answer: two high and two low

step-by-step explanation: because the earth rotates through two tidal “bulges” every lunar day, coastal areas experience every 24 hours and 50 minutes. high tides occur 12 hours and 25 minutes apart.