Question

-5/8(5.6m-1.6n)-7.2(-4/9m+1 7/18 n),если m=10,n=5/18

Answer 1

Раскроем скобки и приведём подобные слагаемые:

= - (5,6·5/8)m + (1,6·5/8)n + (7,2·4/9)m - (7,2·25/18)n =

= - 3,5m + 1n + 3,2m - 10n = (3,2m - 3,5m) - (10n - 1n) =

= - 0,3m - 9n

если m = 10, n = 5/18

- 0,3 · 10 - 9 · 5/18 = - 3 - 5/2 = - 3 - 2,5 = - 5,5

Ответ: - 5,5.

Answer 2

To evaluate the expression, simply substitute the given values of m and n into the expression and perform the calculations step by step.

Given: m = 10 n = 5/18

Now, let's evaluate the expression:

-5/8(5.6m - 1.6n) - 7.2(-4/9m + 1 7/18n)

Step 1: Substitute the values of m and n into the expression:

-5/8(5.6 * 10 - 1.6 * (5/18)) - 7.2(-4/9 * 10 + 1 7/18 * (5/18))

Step 2: Perform the arithmetic operations:

-5/8(56 - 1.6 * (5/18)) - 7.2(-4/9 * 10 + 1 7/18 * (5/18))

Step 3: Continue simplifying:

-5/8(56 - 0.4444) - 7.2(-4/9 * 10 + 0.1543)

Step 4: Calculate the expressions inside the parentheses:

-5/8(55.5556) - 7.2(-0.4444 + 0.1543)

Step 5: Multiply and sum:

-5/8 * 55.5556 + 7.2 * (-0.2901)

Step 6: Calculate the results:

-34.722 - 2.08572

Step 7: Final result:

-36.80772

So, when m = 10 and n = 5/18, the expression evaluates to approximately -36.80772.