fix some printing tests

Author: shashi

test/basics.jl

@@ -173,7 +173,7 @@ end
     @syms a b c
     @test repr(a+b) == "a + b"
     @test repr(-a) == "-a"
-    @test repr(term(-, a; type = Real)) == "-(a)"
+    @test repr(term(-, a; type = Real)) == "-a"
     @test repr(-a + 3) == "3 - a"
     @test repr(-(a + b)) == "-a - b"
     @test repr((2a)^(-2a)) == "(2a)^(-2a)"
@@ -280,8 +280,8 @@ end
 @testset "LiteralReal" begin
     @syms x::LiteralReal y::LiteralReal z::LiteralReal
     @test repr(x+x) == "x + x"
-    @test repr(x*x) == "x*x"
-    @test repr(x*x + x*x) == "x*x + x*x"
+    @test repr(x*x) == "x * x"
+    @test repr(x*x + x*x) == "(x * x) + (x * x)"
     for ex in [sin(x), x+x, x*x, x\x, x/x]
         @test typeof(sin(x)) <: BasicSymbolic{LiteralReal}
     end