How do you evaluate x^3 - 2y^2 - 3x^3 + z^4x3−2y2−3x3+z4 if x = 3, y = 5, and z = -3?
1 Answer
Jul 18, 2016
-23
Explanation:
By substituting the given numeric values for x,y and z into the expression.
That is
(3)^3-2(5)^2-3(3)^3+(-3)^4(3)3−2(5)2−3(3)3+(−3)4
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I'll evaluate each term separately.
(3)^3=3xx3xx3=9xx3=27(3)3=3×3×3=9×3=27
2(5)^2=2xx(5xx5)=2xx25=502(5)2=2×(5×5)=2×25=50
3(3)^3=3xx(3xx3xx3)=3xx27=813(3)3=3×(3×3×3)=3×27=81
(-3)^4=[(-3)xx(-3)]xx[(-3)xx(-3)]=9xx9=81(−3)4=[(−3)×(−3)]×[(−3)×(−3)]=9×9=81
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Replace these values back into the expression , noting the values which are subtracted.
rArr27-50-cancel(81)+cancel(81)=27-50=-23
