7√7
using the ' rule of radicals '
• √a × √b ⇔ √ab
simplifying the radicals
√28 = √(4 × 7 ) = √4 × √7 = 2√7
√63 = √(9 × 7) =√9 × √7 = 3√7
√112 = √(16 × 7 ) = √16 × √7 = 4√7
substituting into the expression
3(2√7) - 5(3√7) + 4(4√7) = 6√7 - 15√7 + 16√7 = 7√7
Answer:
Step-by-step explanation yes
Be sure to include the "=" sign: <span>f(x) = 2^x -7
To find the x-intercepts, set f(x) = 0 and solve for x: 2^x - 7 = 0,
or
2^x = 7
Take the common log of both sides: x log 2 = log 7
log 7
Solve for x: x = --------- = 2.81 (approx)
log 2
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