7(tan(a+b))=5(tan(a+b)) then find the value of sin2a/sin2b

What is the number 321,000,000 in scientific notation? also what is the number? ?

Astudy claims that the mean age of online dating service users is 40 years. some researchers think this is not accurate and want to show that the mean age is not 40 years. identify the null hypothesis, h0, and the alternative hypothesis, ha, in terms of the parameter μ. select the correct answer below: h0: μ≥40; ha: μ< 40 h0: μ≤40; ha: μ> 40 h0: μ≠40; ha: μ=40 h0: μ=40; ha: μ≠40

Match each function with the corresponding function formula when h(x) = 5 - 3x and g(x) = -3 x + 5. 1. k(x) = (3g + 5h)(x) 2. k(x) = (h - g)(x) 3. k(x) = (g + h)(x) 4. k(x) = (5g + 3h)(x) 5. k(x) = (3h - 5g)(x) 6. k(x) = (5h - 3g)(x)