(d)
Factor.
Multiply.
=m 234 Subtract like radicals. NOW TRY
= 4 m 234 - 3 m 234
= 2 # 2 m 234 - 3 m 234 238 m^3 = 2 m; 2327 m^3 = 3 m
= 2238 m^3 # 4 - 2327 m^3 # 4
22332 m^3 - 23108 m^3
SECTION 8.3 Adding and Subtracting Radicals 515
CAUTION A sum or difference of radicals can be simplified only if the radi-
cals are like radicals.
= 425 223 + 5233
25 + 325 Add like 25 + 523
radicals.
Unlike radicals
cannot be simplified.
Complete solution available
on the Video Resources on DVD
8.3 EXERCISES
Concept Check Fill in each blank with the correct response.
1.Simplifying the expression as , is an application of
the property.
2.The radicals and are examples of like radicals because both radicals
have the same root index, , and the same radicand,.
- cannot be simplified because the are different.
- cannot be simplified because the are different.
Add or subtract wherever possible. See Examples 1, 2, and 3(a).
- 42316 - 32354 36. 323250 - 423128
26 # 22 + 323 215 # 23 + 225
23 # 27 + 2221 213 # 22 + 3226
5
8
2128 -
3
4
2160
3
5
275 -
2
3
245
2
3
227 +
3
4
248
1
4
2288 +
1
6
272
5272 - 3248 - 42128 4250 - 3212 - 52200
9224 - 2254 + 3220 228 - 5232 + 2248
6218 - 4232 527 - 2228 + 6263 3211 - 3299 + 5244
2275 - 212 2227 - 2300 2250 - 5272
322 + 250 26 + 27 214 + 217
217 + 2217 219 + 3219 523 + 212
622 - 822 26 + 26 211 + 211
223 + 523 625 + 825 427 - 927
4232 + 322
22 - 223
243 xy^3 - 6243 xy^3
522 + 622 15 + 6222 , or 11 22
NOW TRY
EXERCISE 3
Simplify. Assume that all
variables represent nonnega-
tive real numbers.
(a)
(b)
(c)
(d)
NOW TRY ANSWERS
- (a) (b)
(c)- 2 k^223 (d) 14 y 232 y^2
1222 926 x
23128 y^5 + 5 y 2316 y^2
5 k^2212 - 4227 k^4
2150 x+ 2224 x
27 # 214 + 522